Two Novel, Co-Inherited, Telomerase Reverse Transcriptase (TERT) Mutations Resulting in Inherited Aplastic Anemia and Telomere Shortening

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1607-1607
Author(s):  
Diane J. Nugent ◽  
Matthew A Kunicki ◽  
Shirley A Williams
Keyword(s):  
Bone Marrow ◽  
Amino Acid ◽  
Aplastic Anemia ◽  
Telomere Length ◽  
Megaloblastic Anemia ◽  
Unaffected Sibling ◽  
Exon 2 ◽  
Tert Gene ◽  
History Of ◽  
Compound Heterozygotes

Abstract Inherited aplastic anemia syndromes generally present early in the first decade of life with tri-lineage bone marrow failure. Patients with a more gradual presentation of marrow failure may be missed in later childhood or misdiagnosed as a primary thrombocytopenia or neutropenia syndromes. This family cohort demonstrates a very slow evolution of inherited aplastic anemia thus suggesting that marrow failure with shortened telomere length be considered in the initial work up of unexplained mild to moderate thrombocytopenia and megaloblastic anemia. Patients: A family is described where 3 of 4 children developed aplastic anemia, of varying intensity, over a period of 5-6 years starting at age 10 years. The onset was slow initially with the two oldest children presenting with only mild thrombocytopenia initially (30-40,000 ul/ml) picked up on routine screening at ages 10 yr, female, and 12y, male siblings . They remained stable for a period of two–three years, however with monitoring it became evident that they were developing a mild megaloblastic anemia after 5 years The whole family was screened and an additional child was found to have mild megaloblastic changes and a platelet count of 100,000 ul/ml (9 yr Male). All three affected children demonstrated tri-lineage failure on bone marrow biopsy, but cytogenetic studies and breakage studies were all normal. The parents and a younger sister had normal complete blood counts. There was no history of consanguinity, but detailed family history revealed premature greying of the hair, and pulmonary fibrosis on the paternal side in three generations, although the father is currently unaffected. On the maternal side of the family there is a history of bleeding in maternal aunts, uncles and grandfather, but the mother only has a history of anemia with pregnancy or dieting. On physical exam all patients with aplastic anemia have premature greying of the hair in their twenties but are otherwise normal in appearance without dysmorphic features or skeletal abnormalities. Genetic and Telomere Analysis: Initial workup included analysis for inherited aplastic anemia including Fanconi, Shwachmann Diamond variants, Dyskeratosis Congenita, and Congenital Amegakaryocytosis all of which were negative. With Telomere length (TL) analysis, all three affected patients were found to have Telomere Lengths far less than the first percentile, while the parents and the unaffected sibling were normal for age (Repeat Diagnostics, Vancouver). Additional gene sequencing of WRAP 53, DKC1, NHP2, NOP10, TERC, and TERT was performed on the index case (Ambrey Genetics, Aliso Viejo, CA), and all genes were normal except for TERT, where he was found to be compound heterozygote for two novel TERT mutations in exon 2 at codons F101L and R312W. Family studies revealed that the mother carried the codon R312W mutation, and the father carried the F101L variant. All affected aplastic anemia siblings were also compound heterozygotes and the unaffected sibling had neither mutation. Familial testing confirms that these alterations are on opposite chromosomes (in trans). The codon F101L variant located in exon 2 of the TERT gene, results in phenylalanine being replaced by leucine, an amino acid with highly similar properties. The codon R312W variant is also located in exon 2 of the TERT gene. In this mutation, the arginine at codon 312 is replaced by tryptophan, an amino acid with very dissimilar properties. Neither variant has been previously reported in population based cohorts including: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. Both mutations are predicted to be deleterious by SIFT in silico analyses. Additional analysis using our qPCR based Telomere Length assay and Telomerase activity confirm the diagnosis and are used to screen for similar TL abnormalities in patients with marrow failure. Conclusion: Although neither variant alone results in anemia in the carrier parent, in combination, these mutations appear to result in aplastic anemia in offspring who are compound heterozygotes. Previous reports of other mutations in exon 2 of the TERT gene can also result in marrow failure. Whole genome analysis and telomerase expression studies currently underway will help to elucidate the presence of modifying genes which may impact the variable phenotype between affected siblings in this family. Disclosures No relevant conflicts of interest to declare.

Telomere Dysfunction in Bone Marrow Failure.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. SCI-12-SCI-12
Author(s):  
Peter M. Lansdorp
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Aplastic Anemia ◽  
Telomere Length ◽  
Bone Marrow Failure ◽  
Tumor Development ◽  
Dyskeratosis Congenita ◽  
Cell Numbers ◽  
Tert Gene

Abstract Abstract SCI-12 In order to distinguish a normal telomere from a double strand break, a minimum number of telomere repeats must “cap” each chromosome end. The length of each repeat array will reflect a unique history of addition and losses. Telomere losses are known to occur sporadic as well as with every replication cycle. Losses of telomeric DNA are countered by the telomerase enzyme containing telomerase RNA (encoded by the TERC gene) and a reverse transcriptase protein (encoded by TERT gene) as minimal components. Telomerase levels are high in cells of the germline and immortal cellines and the telomere length is typically maintained in such cells. In contrast, telomerase activity is limiting in most human somatic (stem) cells and as a result the average length of telomere repeats in most somatic cells shows a highly significant decline with age. The hypothesis that loss of telomere repeats acts as a “mitotic clock” and a tumor suppressor mechanism in stem cells is strongly supported by recent studies of patients with mild telomerase deficiency resulting from haplo-insufficiency for either the TERC or TERT gene. Such genetic defects can give rise to various disorders including autosomal dominant Dyskeratosis Congenita (DKC), aplastic anemia, liver fibrosis and pulmonary fibrosis. Other recent studies have revealed that amplification of the hTERT gene is one of the most common genetic abnormalities in various cancers. Paradoxically, it is becoming clear that SNPs within the TERT locus are among the most reproducible risk factors for the development of different types of cancer including lung cancer, acute myeloid leukemia and chronic lymphocytic leukemia. The links between hypo- and hyperproliferative consequences of inborn telomerase deficiencies and SNP's in the TERT gene are poorly understood. It seems plausible that the increased risk of leukemia development in aplastic anemia, myelodysplastic syndrome and Dyskeratosis Congenita, results from stem cell failure. Could reduced stem cell numbers by itself provide a risk factor for tumor development? More direct measures of stem cell numbers in vivo are needed to examine this possibility and the relationship between stem cell numbers and tumor development in patients with defective telomere maintenance as well as in normal individuals as a function of age. Measurements of the average telomere length as well as the length of telomere repeats at individual chromosome ends in specific cells and tissues will further calrify the involvement of telomeres in bone marrow failure, normal aging and tumor biology. Disclosures Lansdorp: Repeat Diagnostics Inc.: Equity Ownership.

of the Telomerase RNA (TERC) and Telomerase Reverse Transcriptase (TERT) in Japanese Children with Aplastic Anemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3750-3750
Author(s):  
Juan Liang ◽  
Hirosi Yagasaki ◽  
Koji Kato ◽  
Kazuko Kudo ◽  
Seiji Kojima
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Bone Marrow Failure ◽  
Unrelated Donor ◽  
Allogeneic Bone ◽  
Healthy Controls ◽  
Japanese Children ◽  
Ribonucleoprotein Complex ◽  
Base Substitutions ◽  
Tert Gene

Abstract It is well known that the incidence of aplastic anemia (AA) is much higher in Japan than in Western countries. However the reason for this finding is not known. Genetic backgrounds related to AA may be different between populations. Recent studies have shown that some patients with apparently “acquired” AA have mutations in telomerase ribonucleoprotein complex genes such as TERC and TERT. We studied 96 Japanese children with acquired AA (age range, 0–16 years; median, 7 years) and 59 healthy controls for mutations in TERC and TERT genes. Of these children, 35 were classified as having nonsevere AA, 39 as having severe AA, and 22 as having very severe AA. In 7 patients, AA was secondary to acute hepatitis. We extracted DNA samples from peripheral blood and all exons and flanking introns of TERT and TERC were amplified by PCR using 19 primer pairs (1 TERC, 18 TERT). To determine the sequence, the PCR products were analyzed by ABI/PRISM 3100 automated sequencer. Telomere lengths of leukocytes were assessed by flow-FISH. For the TERC gene, no mutation was found. One polymorphism (n514 G>A) was observed in 57/96 (59.4%) of patients. The same substitutions were detected in 31/59 (52.5%) healthy controls. For the TERT gene, two novel heterozygous, nonsynonymous mutations were identified (exon5; n2045 G>A, exon6; n2177 C>T). These base substitutions introduce an amino acid change-G682D and T726M, respectively. Neither patient had any clinical characteristics suggesting constitutional bone marrow failure syndrome. The n2177C>T substitution was identified in a 9-year-old girl with very severe AA who failed to respond to immunosuppressive therapy. She received an allogeneic bone marrow transplant (BMT) from an unrelated donor, but did not engraft. She was then treated by a second BMT from an HLA haploidentical her mother. Her blood cells had a very short telomere compared with that of age-matched controls. Another patient carrying the n2045G>A substitution had nonsevere AA and did not require any specific medication for 8 years. Six polymorphisms in exons of the TERT gene were identified in 102 unrelated patients (n915 G>A, n2097 C>T, n2520 G>A, n2946 T>C, n3039 C>T, and n3366 G>A). The allele frequencies of these silent base substitutions were 38/192 (19.8%), 3/192 (1.6%), 1/192 (0.5%), 1/192 (0.5%), 57/192 (29.7%), 2/192 (1.0%), respectively. Additionally, we identified 5 polymorphisms in introns of the TERT genes in 64 patients (IVS4+143 A>G, IVS9+11 C>T, IVS13+45 C>T, IVS15+136 G>A, and IVS16+81 C>T). The frequencies were 52/192 (27.1%), 3/192 (1.6%), 7/192 (3.6%), 1/192 (0.5%), and 1/192 (0.5%), respectively. Except for two substitutions (n915G>A and IVS4+143A>G), the other 9 were not listed in the SNP database. We found a few patients with AA carrying mutations of telomerase ribonucleoprotein complex genes. Because the incidence of these mutations is not higher than that in Western populations, this genetic difference does not explain the higher incidence of AA in Japanese children.

Diagnosis of Fanconi Anemia in An Asymptomatic Adult with Mosaicism and a Molecular Explanation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4213-4213
Author(s):  
Blanche P. Alter ◽  
Neelam Giri ◽  
William Hogan ◽  
Monique Johnson ◽  
Susan Olson ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Repair ◽  
Stem Cell ◽  
Aplastic Anemia ◽  
Hematopoietic Stem Cell ◽  
Nonsense Mutation ◽  
Chromosome Breakage ◽  
Splice Mutation ◽  
Hematopoietic Stem ◽  
History Of

Abstract Abstract 4213 INTRODUCTION Fanconi Anemia (FA) is a primarily autosomal recessive disorder with a defective DNA repair pathway associated with mutations in any of 13 genes. The majority of patients reported in the literature have one or multiple congenital anomalies, including low birth weight, short stature, café au lait spots, abnormal radii and/or thumbs, structural renal abnormalities, microcephaly, and deafness, among others. About 25% of reported patients had few or none of these findings. The hazard of severe aplastic anemia peaks at 10 years of age, and patients have very high risks of acute myeloid leukemia and specific solid tumors, such as head and neck and gynecologic squamous cell carcinomas. Only six patients have been reported who were diagnosed between 40 and 50 years of age. However, patients may present as adults with neoplasms, or remain asymptomatic and undiagnosed. METHODS We report the diagnosis of FA in the oldest known patient, an asymptomatic 55 year old woman (Case 2), identified only because she was a potential stem cell donor for her 42 year old sister (Case 1) with severe aplastic anemia. RESULTS Case 1 had a history of thrombocytopenia at 26, and anemia and thrombocytopenia during pregnancy; physical exam was normal except for a slightly deformed thumb; blood lymphocyte chromosome aberrations were increased with both diepoxybutane (DEB) and mitomycin C (MMC). The patient died following an HLA-matched bone marrow transplant from a non-FA brother. Case 2, the other of two siblings of Case 1 who were HLA matches, had higher than normal chromosome breakage in blood (3 cells with multiple radials with MMC) but not in the FA range; skin fibroblasts were diagnostic of FA, confirming hematopoietic somatic mosaicism. She had a normal appearance, a history of hypothyroidism and mitral valve prolapse, five pregnancies with five children (one miscarriage, one set of twins), a near normal blood count (Hb 13.3 g/dl, MCV 99 fl, WBC 3500/ul, and platelets 139,000/ul), and was a regular blood donor. Bone marrow cellularity and morphology were normal, but cytogenetics showed a small clone (46,XX,add(11)(q23)[6]/46,XX[14]). Complementation analysis of Case 1 indicated group A (FA-A), and molecular analysis identified two mutations in the FANCA gene. One mutation, p.S1208S (c.3624C>T) was a splice site mutation occurring in exon 36 and has been previously described. The second mutation was a novel nonsense mutation in exon 23, p.S674X (c.2021C>A). Five siblings had normal breakage results; four were heterozygous for the nonsense mutation and one was negative for both mutations. Case 2, with mosaicism for FA, had the familial splice mutation in both blood and fibroblasts, and the familial nonsense mutation in fibroblasts, but was skewed heavily toward wild-type in blood. cDNA studies confirmed that the predicted splice mutation created an alternate splice site resulting in multiple transcripts, including exon skipping, which varied in different tissues. The molecular mechanism for the loss of the nonsense mutation in the blood is most likely due to back mutation at a hot spot, which occurred in a hematopoietic stem cell which then had a selective growth advantage. CONCLUSIONS Reversion of one FANCA mutation probably occurred in a hematopoietic stem cell which was selected for and repopulated the peripheral blood. A plausible explanation for the lack of FA clinical features is the leaky splice mutation which may provide sufficient levels of protein for normal function in DNA repair. Family members should be tested for FA by chromosome breakage analysis in blood (and/or fibroblasts to identify those who may be mosaics). Those who have FA are at risk of syndrome-specific solid tumors, as well as aplastic anemia, myelodysplastic syndrome, and leukemia, if a non-gene corrected hematopoietic stem cell were to emerge. Even if asymptomatic, they should not be used as stem cell transplant donors for siblings with FA, because they may fail to repopulate the recipient marrow. FA is undoubtedly underdiagnosed in adults at this time. Disclosures: No relevant conflicts of interest to declare.

Telomerase Gene Mutation Screening and Telomere Length Detection in Chinese Patients with Bone Marrow Failure Syndrome.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1047-1047
Author(s):  
Bing Han ◽  
Bo Liu ◽  
Yongqiang Zhao
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Small Group ◽  
Telomere Length ◽  
Gene Mutation ◽  
Bone Marrow Failure ◽  
Chinese Patients ◽  
Chinese People ◽  
Bone Marrow Failure Syndrome ◽  
Tert Mutation

Abstract Background Acquired bone marrow failure syndrome (BMF) is a group of diseases include aplastic anemia(AA), melodysplastic syndrome (MDS) and paraoxymal nocturnal hemoglobinuria (PNH). Some BMF patients have short telomeres in their peripheral nucleated cells. The length of telomere is maintained by a group of enzymes called telomerase complex. The core components of this complex are a RNA template and a reverse transcriptase, called TERC and TERT, respectively. Recently several studies in the west and Japan have disclosed the presence of telomerase complex gene mutation in a small group of patients with acquired bone marrow failure. They speculated that this small group of patients might represent a subset of cryptogenic Dyskeratosis Congenita (DKC), in which the premature exhaustion of hematopoietic reservoir is caused by mutations in the telomerase gene. This group of patients, though very small in number, would benefit from early bone marrow transplantation instead of traditional immunosuppressive therapy. The incidence of aplastic anemia in Chinese people is relatively high compared with that in the western country. But there has so far been no study in China about the incidence of telomerase gene mutation in acquired bone marrow failure and its relationship with telomere length. Objectives To study the incidence of telomerase gene (namely TERC and TERT ) mutation in Chinese patients with acquired bone marrow failure and explore its relationship with telomere shortening. Methods Blood samples from 90 patients with AA, MDS, and PNH in northern China were collected and performed TERC and TERT mutation analysis. Telomere length was measured by Southern blotting and compared with their normal counterparts. Results 2 TERC mutations (n37 A→G, reported previously ; n66G→C) and 2 TERT mutations (n1870G→T (E/*); n1780G→T (S/I) ) were identified in 90 BMF patients. Among them, 3 mutations are reported first time. 1 patient with TERT mutation, however, was finally diagnosed as DKC instead of acquired AA, making the incidence of telomerase gene mutation in Chinese people with acquired bone marrow failure 3.4%, similar to that of the western people. Southern Blot analysis showed the small group of patients carrying TERC and TERT mutations has very short telomeres, compared with normal controls and with their aplastic counterparts. Conclusions The incidence of telomerase gene mutation in Chinese people with acquired bone marrow failure is 3.4%, similar to that of the western people. This small group of patients has very short telomeres, it is thus clinically important to screen for this small group of patients.

Significance of Telomere Length Measurement in the Diagnosis of Dyskeratosis Congenita.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 836-836
Author(s):  
Hong-Yan Du ◽  
Elena Pumbo ◽  
Akiko Shimamura ◽  
Adrianna Vlachos ◽  
Jeffrey M. Lipton ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Telomere Length ◽  
Bone Marrow Failure ◽  
Skin Pigmentation ◽  
Screening Method ◽  
Dyskeratosis Congenita ◽  
Telomere Maintenance ◽  
Healthy Controls ◽  
Mutation Carriers

Abstract Dyskeratosis congenita (DC) is a rare inherited bone marrow failure (BMF) syndrome. The classical features of DC include nail dystrophy, abnormal skin pigmentation, and mucosal leukoplakia. The diagnosis of DC can be difficult. Originally, the diagnosis was based on the presence of the classical mucocutaneous features. However, the identification of four genes responsible for DC (DKC1, TERC, TERT, and NOP10) showed that these mucocutaneous features are only present in a proportion of patients with DC. Additionally, screening for mutations in the affected genes is expensive and is negative in about 50% of patients with classical features of DC. The products of the genes mutated in DC are the components of the telomerase ribonucleoprotein complex, which is essential for telomere maintenance. Therefore it has been postulated that DC is a disease arising from excessive telomere shortening. Here we examined whether the measurement of telomeres could be used as a screening test to identify individuals with DC. For this purpose we examined telomere length in peripheral blood mononuclear cells from 169 patients who presented with bone marrow failure including 17 patients with DC, diagnosed by the presence of classical cutaneous features or the identification of mutations in DKC1, TERC or TERT, 28 patients with paroxysmal nocturnal hemoglobinuria, 25 patients with Diamond Blackfan anemia, 5 patients with Shwachman-Diamond syndrome, 8 patients with myelodysplastic syndrome, and 74 patients with aplastic anemia of unknown cause classified as idiopathic aplastic anemia. In addition we measured telomere length in 12 patients with idiopathic pulmonary fibrosis and in 45 individuals with a de novo deletion of chromosome 5p including the TERT gene. Their telomere lengths were compared with those of 202 age-matched healthy controls. Moreover, mutations were screened in the genes associated with DC. In cases where a mutation was identified, telomere length and mutations were also examined in all the family members. Our results show that all patients with DC and bone marrow failure have very short telomeres far below the first percentile of healthy controls. Not all mutation carriers, including some carriers of apparently dominant mutations, have very short telomeres. What is more, very short telomeres could be found in healthy individuals in these families, some of whom were not mutation carriers. These findings indicate that in patients with BMF the measurement of telomere length is a sensitive screening method for DC, whether very short telomeres in this setting are also specific for DC remains to be determined. However, in contrast to a previous study, we find that telomere length does not always identify mutation carriers in the families of DC.

Disrupted Lymphocyte Homeostasis in Hepatitis-Associated Acquired Aplastic Anemia Is Associated with Very Low Telomere Lengths

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2408-2408
Author(s):  
Anne-Laure Grignon ◽  
Daria V. Babushok ◽  
Li Yimei ◽  
Helge Hartung ◽  
Ho-Sun Lam ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Telomere Length ◽  
Disease Severity ◽  
Bone Marrow Failure ◽  
Genetic Defect ◽  
Telomere Maintenance ◽  
Wilcoxon Test ◽  
Significant Difference ◽  
Lymphocyte Homeostasis

Abstract Acquired aplastic anemia (AA) is a hematologic disorder characterized by low blood counts and a hypocellular bone marrow, caused by autoimmune destruction of early hematopoietic cells. The diagnosis of AA is made by excluding other disorders that can present with bone marrow failure (BMF). Such disorders include dyskeratosis congenita (DC), a multisystem BMF syndrome, caused by an inherited defect in telomere maintenance. Although classical DC presents in childhood with stereotypical mucocutaneous changes, milder forms of telomere dysfunction associated with mutations in TERT and TERC genes can present with non-syndromic bone marrow failure clinically indistinguishable from AA. In clinical practice, lymphocyte telomere length measurements are used as a first-line screen for inherited telomeropathies before initiating treatment for AA. In our BMF center, we have observed that several patients with features of hepatitis-associated AA (HAA) had lymphocyte telomere lengths at diagnosis at or below the first percentile of age-matched controls, in the range similar to inherited telomere disorders. To confirm our initial observation, we performed a retrospective analysis of telomere lengths of consecutively enrolled HAA patients with non-hepatitis associated AA patients in our institution. A total of 30 patients with AA were included in this study: 10 had HAA and 20 had other AA (Table 1). The median age at telomere testing was 8.0 years (range 1-19 years). There was no significant difference in age or disease severity between the two groups (p=0.827). The patients' median lymphocyte telomere length (TL) was significantly lower in the HAA patients compared to AA (7.4kb versus 9.1kb, P= 0.021); the difference remained significant after adjusting for patient age (p<0.001). Strikingly, 5 of 10 HAA patients had telomeres at or below the 1st percentile of age-matched normal controls, within the diagnostic range for telomeropathies (Figure 1A). None of these 5 patients had clinical features of DC. As a comparison, TL measurements of genetically-confirmed DC patients (Figure 1) demonstrated TL below the 1st percentile for age-matched controls, and within a similar range to that seen in the HAA patients. To ensure that the significantly lower telomere lengths in the HAA patients were not caused by an occult TERT or TERC gene mutation, the five HAA patients with TL below the 1st percentile were screened for germline mutations in TERT and TERC. A known heterozygous polymorphism, Ala1062Thr was found in one patient, a known variant with no known telomere defect and no effect on telomere length. Because differences in lymphocyte activation and subset composition are known to impact telomerase activity, we hypothesized that alterations in lymphocyte populations caused by the unique inflammatory state of HAA could partly account for significantly shorter TL in this population. HAA patients exhibited significantly lower absolute lymphocyte counts and lower lymphocyte subsets across the board, as well as the decreased CD4/CD8 ratio compared to non-hepatitis AA patients (Figure 2). The median telomere length in the two groups was significantly correlated with lymphocyte counts (Pearson correlation coefficient 0.52, p=0.003). An altered lymphocyte homeostasis such as the one characteristic for HAA limits the specificity of telomere measurements as a screening method to identify patients with AA due to a genetic defect in telomere maintaining genes. As such, short telomeres in HAA in the absence of other features suggestive for DC does not necessarily warrant genetic testing for telomere length. Longitudinal studies of telomeres and study of clonal hematopoiesis in this population is ongoing. Table 1. Overall (n = 30) AA (n=20) HAA (n=10) P value* Patient Characteristic Gender, female n (%) 12 (40) 9 (45) 3 (30) 0.694 Gender, male n (%) 18 (60) 11 (55) 7 (70) Age at diagnosis, y, median (range) 8.0 (1-19) 8.3 (1-19) 7.5 (3-17) 0.827 Disease Severity, n (%) 0.999 Moderate 6 (20) 4 (20) 2 (20) Severe 22 (73) 15 (75) 7 (70) Very Severe 2 (7) 1 (5) 1 (10) Median Lymphocyte Telomere Length, kb (range) 8.9 (5.9-11.3) 9.1 (7.5-11.3) 7.4 (5.9-9.8) 0.021 ≤ 1st percentile of age-matched controls 5 0 5 1-10th percentile of age-matched controls 5 5 0 > 10th percentile of age-matched controls 20 15 5 *P-values are obtained by Fisher's exact test for gender and disease severity and by Wilcoxon test for age and telomere length. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures No relevant conflicts of interest to declare.

Very Severe Aplastic Anemia Due to Doxycycline Therapy

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4794-4794
Author(s):  
Prabhsimranjot Singh ◽  
Ankur Sinha ◽  
Anisha Kamath ◽  
Sonali Malhotra ◽  
Abhinav B Chandra
Keyword(s):  
Bone Marrow ◽  
Family History ◽  
Aplastic Anemia ◽  
Skin Rash ◽  
Conflicts Of Interest ◽  
Severe Aplastic Anemia ◽  
Packed Red Blood Cells ◽  
First Case ◽  
History Of ◽  
Cellular Bone

Abstract Very severe aplastic anemia due to doxycycline therapy A 42 y/o male presented to the emergency department with 3 weeks history of fatigue and epistaxis. On initial blood work he was found to have pancytopenia with hemoglobin of 4.7g/dl, platelet count of 4,000 and absolute neutrophil count of 160. He has no significant family history. His past medical history was only significant for a skin rash, which was biopsied 3 months ago and reported to be follicular dermatitis. The only home medication he has taking was doxycycline 100mg twice a day for the past few weeks before the current hospital admission. He was transfused with packed red blood cells and platelets to maintain hemodynamic stability. His bone marrow biopsy was reported to be hypocellular (<5% cellularity) with normal morphological features (see figure 1). Paroxysmal nocturnal hemoglobinuria was ruled out by flow cytometry. Workup including HIV, EBV, Hepatitis B and C and parvovirus serology was reported to be negative. His history of long-term Doxycycline use as well as no family history of any similar disorder, it is plausible that doxycycline could have caused his aplastic anemia. In congruence with the above mentioned findings, he is diagnosed with very severe aplastic anemia and is planned to be started on immunosuppressive therapy with equine anti-thymocyte globulin and cyclosporine along with consultation for allogeneic transplant. Aplastic anemia is a remarkably rare but serious adverse effect of drug therapy like antimicrobials. We report this as the first case, to the best of our knowledge based on the literature review, of possible doxycycline induced severe aplastic anemia. Our patient had history of skin rash for which he was taking doxycycline for few weeks before he presented with pancytopenia. Acquired aplastic anemia is a rare hematological disorder presenting with pancytopenia and a predominantly empty marrow. It is a fatal disease and irrespective of the etiology, without treatment, patients usually succumb due to infection and bleeding. Cases have been reported with tetracycline as a causative agent of aplastic anemia. We hypothesize doxycycline to be the possible etiology of severe aplastic anemia in this patient. Practitioners need to be aware of this rare but fatal complication of this widely used antibiotic. Figure 1. Hypo-cellular Bone Marrow Figure 1. Hypo-cellular Bone Marrow Disclosures No relevant conflicts of interest to declare.

Telomere Length and Telomerase Assay Assist in Identifying Novel Telomere Gene Complex Mutations in a Cohort of Patients with Aplastic Anemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 667-667
Author(s):  
Shreyans Gandhi ◽  
Jie Jiang ◽  
Nana Benson-Quarm ◽  
Hanna Renshaw ◽  
Syed A Mian ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Family History ◽  
Telomere Length ◽  
Mutation Analysis ◽  
Family Members ◽  
Telomerase Activity ◽  
Wild Type ◽  
Trap Assay ◽  
Novel Variants ◽  
History Of

Abstract Background Shortened telomeres are seen in approximately a third of patients with idiopathic aplastic anemia (AA) and they also define risk of relapse, clonal evolution and overall survival. Constitutional pathogenic mutations in the telomere gene complex (TGC) are associated with very short telomeres (typically <1st centile) and may also present with AA, but have important implications in terms of different management strategies, especially with conditioning regimen and donor selection for bone marrow transplantation, which in turn affect transplant outcomes. Furthermore, detection of mutations of the TGC complex then entail regular screening/review of organ/systems affected in telomere disease, counselling and health insurance with regards to the increased risk of cancer and screening of family members. Novel variants affecting telomere function are increasingly being reported but in the absence of a full telomere disease phenotype, unaffected family members or variable penetrance of the mutant in affected family members, there remains uncertainty as to whether some are pathogenic or represent polymorphisms. Methods We report results using telomere length (TL) measurement by quantitative-real time PCR (qPCR) as a screening tool to identify patients for further mutation analysis on a customised panel of 10 TGC genes (TERT, TERC, DKC1, TINF2, NHP2, NOP10, RTEL1, CTC1, USB1 and WRAP) using deeply parallel sequencing in a cohort of patients with AA. Using a Polyphen score that predicts a variant to be possibly pathogenic, we have used telomere repeat amplification protocol (TRAP) assay to increase the robustness of classifying a variant as more likely pathogenic, where family history was unrevealing. TRAP assay was performed by introducing the variants into W138V13 cell line and comparing telomerase expression in them to wild type TERT and TERC expression of telomerase. Results From the King's College Hospital database, we screened 295 patients with AA for TL using qPCR. The median age of the cohort was 44.2 years (range18.2- 83.4) with male/female ratio of 57:43. 189 patients (64%) had TL < 10th centile and 111 (37.6%) had TL <1st centile (Figure 1). We screened 215 of these patients for TGC mutation analysis and report 40 mutations (18.6%) in this cohort. Most mutations were in the reverse transcriptase enzyme TERT (n=33) and the remaining in the catalytic unit of the RNA complex TERC (n=7). A positive family history of bone marrow failure was seen in only 4 (10%) of these cases with TGC mutation, where the same TGC mutation was detected. 38/40 (95%) patients with a TGC mutation had a TL <10th centile and 32 (80%) had TL<1st centile. 32/111 (28.8%) of AA patients with TL<1st centile were found to have a TGC mutation, while only 6/78 (7.8%) of AA patients with 10th < TLth centile had TGC mutations. We identified a further 9 novel variants which were predicted to be possibly pathogenic, but have not been reported pathogenic in literature, as yet. All 9 patients with the novel variants had TL <1st centile with a median age of 37 (range 19-62), but had no positive family history of bone marrow failure or features of telomere disease. Using the TRAP assay, all 9 variants had telomerase activity well below 50% of WT TERT and TERC telomerase expression. All TERC variants had TRAP score of ~20% and 5 of the 6 TERT variants had TRAP score of <30% of WT TERT telomerase activity, of which 3 had telomerase activity <5% (Figure 2). Conclusion Two thirds of patients with AA have TL <10 th centile. Most patients with a TGC mutation have TL <1st centile. TL can reliably be used as a screening tool to investigate patients for further TGC mutation analysis. Heterozygous state mutation in TERT are the commonest, followed by TERC and explain the slightly late onset (mid 40's) and milder presentation of telomere disease as compared to the more severe phenotype and younger presentation classically seen with the homozygous state DKC mutations. A telomere length and a TRAP assay can add value in predicting a possible or putative pathogenic variant in a TERT or TERC gene on TGC analysis, where a reliable family history of telomereopathy is lacking. Figure 1. Telomere length expressed as T/S ratio against age for the different cohorts Figure 1. Telomere length expressed as T/S ratio against age for the different cohorts Figure 2. Expression of telomerase activity in novel TERT and TERC variants compared to Wild-type (positive control) and Mock (negative control) Figure 2. Expression of telomerase activity in novel TERT and TERC variants compared to Wild-type (positive control) and Mock (negative control) Disclosures Kulasekararaj: Alexion: Consultancy.

scholarly journals Clinico hematological profile of pancytopenia in pediatric patients: an institutional experience in North Himalayan region of India

2020 ◽  
Vol 8 (2) ◽  
pp. 726
Author(s):  
Anil Rawat ◽  
Varun Mamgain ◽  
Smita Chandra ◽  
B. P. Kalra
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Megaloblastic Anemia ◽  
Nutritional Deficiency ◽  
Deficiency Anemia ◽  
Total Leukocyte Count ◽  
Mean Corpuscular Hemoglobin ◽  
Corpuscular Hemoglobin ◽  
Common Cause ◽  
Nutritional Anemia

Background: Pancytopenia is a common clinical pattern with an extensive differential diagnosis, but literature search shows only limited studies of pancytopenia in Pediatrics patients in Uttarakhand state of India. The present study was therefore conducted to study the spectrum of pancytopenia with bone marrow and haematological profile in Pediatrics patients in this north Himalayan state of India.Methods: Prospective observational study was conducted in the Department of Pediatrics in the teaching institute situated in Uttarakhand state of India over a period of 12 months. The study included all the patients of pancytopenia below 18 years of age who underwent bone marrow examination after written informed consent.Results: The study included total 50 pediatrics patients of pancytopenia with male to female ratio of 1.38:1. The mean age of patients was 10.58±4.94 with median age of 12 years. Mean hemoglobin was 5.31±2.09 g/dl, total leukocyte count was 2492.68±941.76/mm3, platelet count was 34724±26423/mm3, mean corpuscular volume was 90.95±16.65 fl, mean corpuscular hemoglobin was 30.11±6.07 pg, mean corpuscular hemoglobin concentration was 33.06±1.65% and reticulocyte count was 1.21±1.10%. Nutritional deficiency (28%) was the most common cause for pancytopenia followed by aplastic anemia (24%). Megaloblastic anemia was the commonest cause of nutritional deficiency anemia (71.42%) with pancytopenia.Conclusions: Pancytopenia is an important presentation in Pediatrics population with the most common cause being nutritional anemia and aplastic anemia. Megaloblastic anemia is the commonest cause of nutritional anemia with pancytopenia. The clinicians should be aware of spectrum of pancytopenia with clinical and haematological presentation in Pediatrics patients of this region so as to avoid unnecessary work ups and delay in treatment.

scholarly journals HAEMATOLOGICAL DISORDERS

2018 ◽  
Vol 25 (06) ◽  
Author(s):  
Muhammad Ihtesham Khan ◽  
Neelam Ahmad ◽  
Syeda Hina Fatima
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Aplastic Anemia ◽  
Hemolytic Anemia ◽  
Myeloid Leukemia ◽  
Megaloblastic Anemia ◽  
Lymphoblastic Leukemia ◽  
Deficiency Anemia ◽  
Female Ratio ◽  
Acute Myeloid

Objectives: To analyse the pattern of hematological disorders through bonemarrow aspiration, and to compare the final diagnoses with their referral diagnoses made by thereferring physicians.Study Design: Cross sectional descriptive study. Period: 1st January -2016to 30th December-2016. Setting: Department of Pathology, Khyber Teaching Hospital, Peshawar.Materials and Methods: 352 patients were included in the study. Bone marrow diagnosiswas recorded. Data was analysed by SPSS version 18 and results were drawn accordingly.Results: A total of 352 patients underwent bone marrow aspiration during the study period.About 15 patients had diluted bone marrow aspirates. So, they were excluded from the study.The remaining 337 patients were included in the study. The age of the study sample rangedfrom 9 months to 72 years (mean age 36 years ±17.8 SD). There were 185 (55%) male and151 (45%) females. Male to female ratio was 1.2:1. The commonest indication for bone marrowaspiration was “suspected malignancy”, which was suspected in 114(33.85) patients, followedby “pancytopenia”, which was seen in 69(20.55%) patients. About 69 (20.5%) patients werereferred for work up of anemia. Bicytopenia was seen in 69(20.5%). The bone marrow aspirationshowed that megaloblastic anemia was the commonest disorder observed in 37(10%) cases.Second common disorder was acute lymphoblastic leukemia, that was seen in 31 (9%) patients,followed by acute myeloid leukemia, which was seen in 26(7.7%) cases. Hemolytic anemia wasseen in 20 (15.9%) cases. Aplastic anemia was seen in 18 (5.3%) cases. Multiple myeloma andmononuclear infiltration was seen in 17 (5%) patients each. Anemia of chronic disorder wasseen in 16(4.7%) cases. Idiopathic Thrombocytopenic Purpura was seen in 12 (3.6%) patients.Iron deficiencyanemia was seen in 11 (3.3%) patients. Chronic Lymphocytic Leukemia wasseen in 10 (2.9), Mixed deficiency anemia in 9 (2.7%), Myelodysplasia in 6 (1.7%), Malaria in5(1.5%), and Niemann Pick in 4 (1.2%) patients. Gaucher disease and Visceral Leishmania wasseen in 2 (0.6%) patients each. Histiocyticlymphohistiocytosis and Chediak Hegashi syndromewas seen in 1 (0.3%) patients each. Conclusions: Megaloblastic anemia, Acute LymphoblasticLeukemia, Acute Myeloid Leukemia, Hemolytic Anemia and Aplastic Anemia are the commonhematological disorders in our set up. Bone marrow is a reliable procedure to diagnosishematological diseases when routine investigations fail to make diagnosis.

Sign in / Sign up

Export Citation Format

Share Document