scholarly journals Very short telomere length by flow fluorescence in situ hybridization identifies patients with dyskeratosis congenita

Blood ◽  
2007 ◽  
Vol 110 (5) ◽  
pp. 1439-1447 ◽  
Author(s):  
Blanche P. Alter ◽  
Gabriela M. Baerlocher ◽  
Sharon A. Savage ◽  
Stephen J. Chanock ◽  
Babette B. Weksler ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Telomere Length ◽  
Bone Marrow Failure ◽  
Correct Diagnosis ◽  
Dyskeratosis Congenita ◽  
Telomere Maintenance

Abstract Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome in which the known susceptibility genes (DKC1, TERC, and TERT) belong to the telomere maintenance pathway; patients with DC have very short telomeres. We used multicolor flow fluorescence in situ hybridization analysis of median telomere length in total blood leukocytes, granulocytes, lymphocytes, and several lymphocyte subsets to confirm the diagnosis of DC, distinguish patients with DC from unaffected family members, identify clinically silent DC carriers, and discriminate between patients with DC and those with other bone marrow failure disorders. We defined “very short” telomeres as below the first percentile measured among 400 healthy control subjects over the entire age range. Diagnostic sensitivity and specificity of very short telomeres for DC were more than 90% for total lymphocytes, CD45RA+/CD20− naive T cells, and CD20+ B cells. Granulocyte and total leukocyte assays were not specific; CD45RA− memory T cells and CD57+ NK/NKT were not sensitive. We observed very short telomeres in a clinically normal family member who subsequently developed DC. We propose adding leukocyte subset flow fluorescence in situ hybridization telomere length measurement to the evaluation of patients and families suspected to have DC, because the correct diagnosis will substantially affect patient management.

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.

Telomere Length Measurement by Flow-FISH Distinguishes Dyskeratosis Congenita from Other Bone Marrow Failure Syndromes.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 183-183
Author(s):  
Blanche P. Alter ◽  
Gabriela Baerlocher ◽  
Sharon A. Savage ◽  
Stephen Jacob Chanock ◽  
Babette B. Weksler ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Telomere Length ◽  
Sensitivity And Specificity ◽  
Bone Marrow Failure ◽  
Correct Diagnosis ◽  
White Blood Cells ◽  
Dyskeratosis Congenita ◽  
Length Measurement ◽  
Specific Method ◽  
Telomere Biology

Abstract This study was designed to evaluate the utility of flow-FISH telomere length measurement in white blood cells (WBC) as a screening test for Dyskeratosis congenita (DC). We studied 26 patients: 17 with DC, 1 silent carrier (clinically normal; mutation in TERC), 4 with the Hoyeraal-Hreidarsson variant (HH), and 4 with Revesz Syndrome. Five had mutations in DKC1, 5 in TERC, and 2 in TERT. 23 had hematologic abnormalities, 19 had 2 or 3 of the DC diagnostic triad (lacey pigmentation, dyskeratotic nails, and leukoplakia), and 4 had soft signs of DC. We evaluated 54 first-degree relatives of DC patients, 16 Fanconi Anemia patients (FA), 14 with Diamond-Blackfan Anemia (DBA), 5 with Shwachman Diamond Syndrome (SDS), and 10 with other possibly inherited cytopenias (Other). Telomere length was measured in granulocytes and lymphocyte subsets by automated multicolor flow-FISH; results were compared with age-matched values from 400 normal controls. “Very low (VL)” telomere length was defined as a mean telomere length below the normal first percentile for age and specific WBC type. We observed VL telomeres in all subsets in the silent carrier, all HH and Revesz patients, and 15/17 with DC. Eight of 51 DC relatives had VL telomeres in granulocytes versus 2/54 with VL telomeres in lymphocytes. The sensitivities for distinguishing a DC patient from an unaffected relative were 92% in lymphocytes and 96% in granulocytes; the specificities were 96% and 98%, respectively; the sensitivity and specificity for VL telomeres in both cell types were 96% and 96%. The silent carrier with a TERC mutation developed thrombocytopenia, hypocellular marrow, and a cytogenetic clone during follow-up. The 2 DC relatives with VL telomeres in lymphocytes were from a family without a known mutant gene; they may also be silent carriers. The latter possibility disqualified an HLA-matched sibling as a donor for DC-related aplastic anemia, because of engraftment concerns; another sibling donor with normal telomere length was selected. VL granulocyte telomeres were observed in 5/16 FA, 3/14 DBA, 1/5 SDS, and 1/10 Other patients, versus 2/16 FA, 1/14 DBA, 1/5 SDS, and 0/10 Other in lymphocytes, and in both lineages in only 1 each of FA, DBA, and SDS. The sensitivity and specificity for distinguishing DC from non-DC patients using VL telomeres in both lineages were 96% and 93%, respectively. Only DC patients had consistently VL telomeres in all cell subsets. Flow-FISH telomere length measurement provides a sensitive and specific method for identifying patients with DC among families, regardless of mutation status, and distinguishes patients with DC from those with other inherited or acquired marrow failure syndromes. It may also help to detect silent carriers, and facilitate identification of mutations in other telomere biology genes. Our data suggest that the diagnostic triad, soft physical findings and/or bone marrow failure may not be required for the diagnosis of DC. Correct diagnosis of DC will enhance genetic counseling and hematologic management.

Very Short Telomeres Are Characteristic of Dyskeratosis Congenita and Not Other Inherited Bone Marrow Failure Syndromes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1044-1044
Author(s):  
Blanche P. Alter ◽  
Gabriela Baerlocher ◽  
Neelam Giri ◽  
Peter M. Lansdorp ◽  
Sharon A Savage
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
Telomere Length ◽  
Bone Marrow Failure ◽  
Dyskeratosis Congenita ◽  
Z Score ◽  
Bone Marrow Failure Syndromes ◽  
Z Scores ◽  
The Mean

Abstract Telomeres protect the ends of chromosomes, shorten with age, and are very short in dyskeratosis congenita (DC), an inherited bone marrow failure syndrome (IBMFS) associated with mutations in telomere biology genes. “Short telomeres” were reported in Fanconi Anemia (FA), Diamond-Blackfan Anemia (DBA) and Shwachman-Diamond Syndrome (SDS) using telomere restriction fragment length or Q-FISH assays of total leukocyte or mononuclear cell DNA. These reports focused on group averages, not results from individual patients. Our objective was to determine which categories of IBMFS patients have very short telomeres, and in which leukocyte subsets, using a more sensitive and specific assay. Telomere length was measured in granulocytes, lymphocytes, naïve T-cells, memory T-cells, B-cells, and NK cells using automated multicolor flow fluorescence in situ hybridization (FISH). We previously showed that very short telomeres (<1st percentile for age) in lymphocytes, naïve T-cells, and B-cells were sensitive and specific for the diagnosis of DC (Alter et al, Blood110:1439, 2007). Granulocytes were not specific, since in that study neutropenic patients without DC often had very short granulocyte telomeres. The current study included 53 DC patients and 87 relatives, 19 non-transplanted FA patients and 12 relatives, 21 DBA patients and 11 relatives, and 7 SDS patients and 7 relatives. There were 400 normal controls, ages 0 to 100; very short telomeres were defined as <1st percentile of normal for age. Z-scores were calculated to adjust for age; 0 is normal and -2 or below is significantly short (i.e. <2 standard deviations below the mean). Lymphocyte telomeres were <1st percentile (very short) in 96% of DC patients, 7% of DC relatives, 16% of FA patients, 5% of DBA patients, 14% of SDS patients, and none of the non-DC relatives. Granulocyte telomeres were very short in 94% of DC patients, 16% of DC relatives, 44% of FA patients, 19% of DBA patients, 14% of SDS patients, 8% of FA relatives, and none of the non-DC relatives. All three hallmark leukocyte subsets (lymphocytes, naïve T-cells, and B-cells) were very short in 81% of DC patients, 5% of DC relatives, 5% of DBA patients, and none of the FA or SDS patients or their relatives. Although 4 out of 47 (9%) IBMFS other than DC had very short telomeres in lymphocytes, only one, a patient with DBA (without mutations in known DC genes) had very short telomeres in all 3 of the hallmark lineages. Four of 87 DC relatives also had very short telomeres in all 3 lineages; they may be silent carriers in families in which DC genes have not yet been identified. The mean Z-score for lymphocyte telomeres in DC was -4.7; it was above -2 in all other categories (-0.3 in FA, -0.9 in DBA, -1 in SDS). The mean Z-score for granulocytes was -4.2 in DC, -1.9 in FA, -1.2 in DBA, and -1.5 in SDS. Thus, based on the Z-scores, the average telomere length was very short in DC lymphocytes and granulocytes; normal in FA lymphocytes and borderline in FA granulocytes; and normal in DBA and SDS lymphocytes and granulocytes. Flow-FISH provides analysis of multiple cell types in individual patients, and identification of specific individuals with very short telomeres, as well as the age-adjusted mean telomere length in a diagnostic subset. No FA or SDS patients, and only one with DBA, met the DC diagnostic criteria of very short telomeres in three or more lymphocyte subsets. The telomere length deficit in DC appears to be more severe and more frequent than in the other inherited bone marrow failure syndromes.

scholarly journals Cell Type–Specific Quantification of Telomere Length and DNA Double-strand Breaks in Individual Lung Cells by Fluorescence In Situ Hybridization and Fluorescent Immunohistochemistry

2018 ◽  
Vol 66 (7) ◽  
pp. 485-495 ◽  
Author(s):  
Aernoud A. van Batenburg ◽  
Karin M. Kazemier ◽  
Ton Peeters ◽  
Matthijs F. M. van Oosterhout ◽  
Joanne J. van der Vis ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Telomere Length ◽  
Dna Sequences ◽  
Double Strand Breaks ◽  
Telomere Maintenance ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

Telomeres are small repetitive DNA sequences at the ends of chromosomes which act as a buffer in age-dependent DNA shortening. Insufficient telomere repeats will be recognized as double-strand breaks. Presently, it is becoming more evident that telomere attrition, whether or not caused by mutations in telomere maintenance genes, plays an important role in many inflammatory and age-associated diseases. In this report, a method to (semi)quantitatively assess telomere length and DNA double-strand breaks in formalin-fixed paraffin-embedded (FFPE) tissue is described. Therefore, a novel combination of quantitative fluorescence in situ hybridization, tissue elution, and immunofluorescence staining techniques was developed. Caveolin-1 (type 1 pneumocytes), pro-surfactant protein C (type 2 pneumocytes), club cell-10 (club cells), and alpha smooth muscle actin (smooth muscle cells) markers were used to identify cell types. To visualize all the different probes, restaining the tissue by heat-mediated slide elution is essential. Fluorescent signals of telomeres and DNA double-strand breaks were quantified using the Telometer plugin of ImageJ. As example, we analyzed lung tissue from a familial pulmonary fibrosis patient with a mutation in the telomere-associated gene poly(A)-specific ribonuclease ( PARN). The protocol displays a novel opportunity to directly quantitatively link DNA double-strand breaks to telomere length in specific FFPE cells.

Early Detection of Relapse by Hypermetaphase Fluorescence In Situ Hybridization After Allogeneic Bone Marrow Transplantation for Chronic Myeloid Leukemia

2000 ◽  
Vol 18 (9) ◽  
pp. 1831-1836 ◽  
Author(s):  
Chy-Myong Seong ◽  
Sergio Giralt ◽  
Hagop Kantarjian ◽  
Jingping Xu ◽  
Jolynn Swantkowski ◽  
...  
Keyword(s):  
Bone Marrow ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Low Frequency ◽  
Allogeneic Bone Marrow ◽  
Myelogenous Leukemia ◽  
Mixed Chimerism ◽  
Allogeneic Bone ◽  
Time Points

PURPOSE: Standard G-band cytogenetic analysis (CG) provides information on approximately 25 metaphases for monitoring the presence of Philadelphia chromosome positive (Ph+) cells in chronic myelogenous leukemia (CML) patients, making the detection of a low frequency of Ph+ cells problematic. The purpose of this study was to improve the detection of a low frequency of Ph+ cells. PATIENTS AND METHODS: We combined fluorescence in situ hybridization (FISH) with long-term colcemid exposure, capturing several hundred metaphases in bone marrow cultures (hypermetaphase FISH [HMF]). Using probes that identify Ph+ cells, HMF was compared with CG analysis in the follow-up evaluations of 51 patients with CML at various time points after allogeneic bone marrow transplant (BMT). RESULTS: Thirty-five patients never showed the presence of Ph+ cells by either method. In four patients, high frequencies of Ph+ cells were detected by both methods. In the remaining 12 patients, Ph+ cells were detected by HMF at time points after BMT when they were not detected by CG. In seven of the 12 patients, low but statistically significant frequencies of Ph+ cells (0.37% to 5.20%) were detected 3 months or later after BMT, and when no intervention was initiated, all seven patients later relapsed. Based on those data, an eighth patient with mixed chimerism and a similar HMF-detected Ph+ frequency (1.8% at 27 months after BMT) was reinfused with donor lymphocytes and achieved remission with 0% Ph+ cells studied by HMF (up to 50 months after BMT). Ph+ cells detected by HMF but not by CG less than 3 months after BMT disappeared on later examination in two of four patients. After detection of Ph+ cells by HMF only, the median time to cytogenetic progression (detection of Ph+ cells by CG) was 101 days. CONCLUSION: The results demonstrate the ability of HMF to detect low but clinically relevant levels of leukemic cells not detected by CG in transplant patients. The data indicate that HMF can detect low levels of Ph+ cells before standard cytogenetics at a time that may be useful in monitoring disease status and planning clinical interventions.

scholarly journals Detection of residual leukemic cells in patients with acute promyelocytic leukemia by the fluorescence in situ hybridization method: potential for predicting relapse

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 495-499 ◽  
Author(s):  
L Zhao ◽  
KS Chang ◽  
EH Estey ◽  
K Hayes ◽  
AB Deisseroth ◽  
...  
Keyword(s):  
Bone Marrow ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Acute Promyelocytic Leukemia ◽  
Bone Marrow Cells ◽  
Residual Disease ◽  
Promyelocytic Leukemia ◽  
Leukemic Cells ◽  
Low Frequencies

Abstract The translocation between chromosomes 15 and 17, t(15;17)(q22–24;q11– 21), is present in the bone marrow cells of most patients with acute promyelocytic leukemia (APL). Although conventional cytogenetic methods are useful for diagnosing this disease, difficulties are experienced in detecting residual disease among those patients who have achieved remission. In this study, we used the fluorescence in situ hybridization (FISH) method to attempt to detect residual leukemic cells in 10 APL patients in clinical remission. The duration of remission ranged from 2 to 93 months at the time of study. Multiple bone marrow samples were analyzed by FISH in most patients. In 6 patients, no cell with t(15;17) was found. These patients remain in complete remission at present (approximately 25 to 33 months since first studied by FISH). In 4 patients, low frequencies of cells with t(15;17) were observed in at least one bone marrow sample examined. All of these patients relapsed within 1 to 14 months. No cell with t(15;17) was identified by the conventional G-banding method in any sample. The FISH results correlated well with that of a two-round nested reverse transcription polymerase chain reaction assay that was performed on the same samples. Thus, our study suggests that FISH is potentially a useful tool for detecting residual APL cells and for identifying patients at high risk of relapse.

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