scholarly journals Clinical spectrum of POLR3-related leukodystrophy caused by biallelic POLR1C pathogenic variants

2019 ◽  
Vol 5 (6) ◽  
pp. e369 ◽  
Author(s):  
Laurence Gauquelin ◽  
Ferdy K. Cayami ◽  
László Sztriha ◽  
Grace Yoon ◽  
Luan T. Tran ◽  
...  
Keyword(s):  
Brain Mri ◽  
Rna Polymerase Iii ◽  
Craniofacial Development ◽  
Treacher Collins Syndrome ◽  
Molecular Characteristics ◽  
Cross Sectional ◽  
Related Disorder ◽  
Pathogenic Variants ◽  
T2 Hyperintensity ◽  
Hypomyelinating Leukodystrophy

ObjectiveTo determine the clinical, radiologic, and molecular characteristics of RNA polymerase III-related leukodystrophy (POLR3-HLD) caused by biallelic POLR1C pathogenic variants.MethodsA cross-sectional observational study involving 25 centers worldwide was conducted. Clinical and molecular information was collected on 23 unreported and previously reported patients with POLR3-HLD and biallelic pathogenic variants in POLR1C. Brain MRI studies were reviewed.ResultsFourteen female and 9 male patients aged 7 days to 23 years were included in the study. Most participants presented early in life (birth to 6 years), and motor deterioration was seen during childhood. A notable proportion of patients required a wheelchair before adolescence, suggesting a more severe phenotype than previously described in POLR3-HLD. Dental, ocular, and endocrine features were not invariably present (70%, 50%, and 50%, respectively). Five patients (22%) had a combination of hypomyelinating leukodystrophy and abnormal craniofacial development, including 1 individual with clear Treacher Collins syndrome (TCS) features. Brain MRI revealed hypomyelination in all cases, often with areas of pronounced T2 hyperintensity corresponding to T1 hypointensity of the white matter. Twenty-nine different pathogenic variants (including 12 new disease-causing variants) in POLR1C were identified.ConclusionsThis study provides a comprehensive description of POLR3-HLD caused by biallelic POLR1C pathogenic variants based on the largest cohort of patients to date. These results suggest distinct characteristics of POLR1C-related disorder, with a spectrum of clinical involvement characterized by hypomyelinating leukodystrophy with or without abnormal craniofacial development reminiscent of TCS.

scholarly journals P.075 Clinical spectrum of POLR3-related leukodystrophy caused by biallelic POLR1C pathogenic variants

2019 ◽  
Vol 46 (s1) ◽  
pp. S34
Author(s):  
L Gauquelin ◽  
FK Cayami ◽  
L Sztriha ◽  
G Yoon ◽  
LT Tran ◽  
...  
Keyword(s):  
Hypogonadotropic Hypogonadism ◽  
Craniofacial Development ◽  
Clinical Spectrum ◽  
Treacher Collins Syndrome ◽  
Cross Sectional ◽  
Related Disorder ◽  
Molecular Features ◽  
Pathogenic Variants ◽  
Motor Difficulties ◽  
Hypomyelinating Leukodystrophy

Background: Biallelic variants in POLR1C are associated with POLR3-related leukodystrophy (POLR3-HLD), or 4H leukodystrophy (Hypomyelination, Hypodontia, Hypogonadotropic Hypogonadism), and Treacher Collins syndrome (TCS). The clinical spectrum of POLR3-HLD caused by variants in this gene has not been described. Methods: A cross-sectional observational study involving 25 centers worldwide was conducted between 2016 and 2018. The clinical, radiologic and molecular features of 23 unreported and previously reported cases of POLR3-HLD caused by POLR1C variants were reviewed. Results: Most participants presented between birth and age 6 years with motor difficulties. Neurological deterioration was seen during childhood, suggesting a more severe phenotype than previously described. The dental, ocular and endocrine features often seen in POLR3-HLD were not invariably present. Five patients (22%) had a combination of hypomyelinating leukodystrophy and abnormal craniofacial development, including one individual with clear TCS features. Several cases did not exhibit all the typical radiologic characteristics of POLR3-HLD. A total of 29 different pathogenic variants in POLR1C were identified, including 13 new disease-causing variants. Conclusions: Based on the largest cohort of patients to date, these results suggest novel characteristics of POLR1C-related disorder, with a spectrum of clinical involvement characterized by hypomyelinating leukodystrophy with or without abnormal craniofacial development reminiscent of TCS.

scholarly journals Mitochondrial diseases in North America

2020 ◽  
Vol 6 (2) ◽  
pp. e402 ◽  
Author(s):  
Emanuele Barca ◽  
Yuelin Long ◽  
Victoria Cooley ◽  
Robert Schoenaker ◽  
Valentina Emmanuele ◽  
...  
Keyword(s):  
North America ◽  
Clinical Care ◽  
Age At Onset ◽  
Nuclear Gene ◽  
Mitochondrial Diseases ◽  
Molecular Characteristics ◽  
Cross Sectional ◽  
Pathogenic Variants ◽  
Common Diagnosis ◽  
Genetic Features

ObjectiveTo describe clinical, biochemical, and genetic features of participants with mitochondrial diseases (MtDs) enrolled in the North American Mitochondrial Disease Consortium (NAMDC) Registry.MethodsThis cross-sectional, multicenter, retrospective database analysis evaluates the phenotypic and molecular characteristics of participants enrolled in the NAMDC Registry from September 2011 to December 2018. The NAMDC is a network of 17 centers with expertise in MtDs and includes both adult and pediatric specialists.ResultsOne thousand four hundred ten of 1,553 participants had sufficient clinical data for analysis. For this study, we included only participants with molecular genetic diagnoses (n = 666). Age at onset ranged from infancy to adulthood. The most common diagnosis was multisystemic disorder (113 participants), and only a minority of participants were diagnosed with a classical mitochondrial syndrome. The most frequent classical syndromes were Leigh syndrome (97 individuals) and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (71 individuals). Pathogenic variants in the mitochondrial DNA were more frequently observed (414 participants) than pathogenic nuclear gene variants (252 participants). Pathogenic variants in 65 nuclear genes were identified, with POLG1 and PDHA1 being the most commonly affected. Pathogenic variants in 38 genes were reported only in single participants.ConclusionsThe NAMDC Registry data confirm the high variability of clinical, biochemical, and genetic features of participants with MtDs. This study serves as an important resource for future enhancement of MtD research and clinical care by providing the first comprehensive description of participant with MtD in North America.

scholarly journals Genetic Neonatal-Onset Epilepsies and Developmental/Epileptic Encephalopathies with Movement Disorders: A Systematic Review

2021 ◽  
Vol 22 (8) ◽  
pp. 4202
Author(s):  
Carlotta Spagnoli ◽  
Carlo Fusco ◽  
Antonio Percesepe ◽  
Vincenzo Leuzzi ◽  
Francesco Pisani
Keyword(s):  
Movement Disorders ◽  
Time Course ◽  
Neonatal Period ◽  
Age Of Onset ◽  
Brain Mri ◽  
Neonatal Seizure ◽  
Mri Findings ◽  
Epileptic Encephalopathies ◽  
Pathogenic Variants ◽  
Neonatal Onset

Despite expanding next generation sequencing technologies and increasing clinical interest into complex neurologic phenotypes associating epilepsies and developmental/epileptic encephalopathies (DE/EE) with movement disorders (MD), these monogenic conditions have been less extensively investigated in the neonatal period compared to infancy. We reviewed the medical literature in the study period 2000–2020 to report on monogenic conditions characterized by neonatal onset epilepsy and/or DE/EE and development of an MD, and described their electroclinical, genetic and neuroimaging spectra. In accordance with a PRISMA statement, we created a data collection sheet and a protocol specifying inclusion and exclusion criteria. A total of 28 different genes (from 49 papers) leading to neonatal-onset DE/EE with multiple seizure types, mainly featuring tonic and myoclonic, but also focal motor seizures and a hyperkinetic MD in 89% of conditions, with neonatal onset in 22%, were identified. Neonatal seizure semiology, or MD age of onset, were not always available. The rate of hypokinetic MD was low, and was described from the neonatal period only, with WW domain containing oxidoreductase (WWOX) pathogenic variants. The outcome is characterized by high rates of associated neurodevelopmental disorders and microcephaly. Brain MRI findings are either normal or nonspecific in most conditions, but serial imaging can be necessary in order to detect progressive abnormalities. We found high genetic heterogeneity and low numbers of described patients. Neurological phenotypes are complex, reflecting the involvement of genes necessary for early brain development. Future studies should focus on accurate neonatal epileptic phenotyping, and detailed description of semiology and time-course, of the associated MD, especially for the rarest conditions.

Changes in brain MRI under different lunar cycles: a cross-sectional study

2021 ◽  
pp. 1-7
Author(s):  
Ayyoub Malek ◽  
Mohammad Hossein Daghighi ◽  
Masoud Pourisa ◽  
Tohid Pourmohammadi ◽  
Saeed Dastgiri ◽  
...  
Keyword(s):  
Brain Mri ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Lunar Cycles

Fish Intake and MRI Burden of Cerebrovascular Disease in Older Adults

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012916
Author(s):  
Aline Thomas ◽  
Fabrice Crivello ◽  
Bernard Mazoyer ◽  
Stephanie Debette ◽  
Christophe Tzourio ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Cerebrovascular Disease ◽  
Brain Mri ◽  
Large Population ◽  
Population Based ◽  
Fish Intake ◽  
Mixed Data ◽  
Perivascular Spaces ◽  
Intracranial Volume ◽  
Cross Sectional

Background and Objective:Fish intake may prevent cerebrovascular disease (CVD), yet the mechanisms are unclear, especially regarding its impact on subclinical damage. Assuming that fish may have pleiotropic effect on cerebrovascular health, we investigated the association of fish intake with global CVD burden based on brain MRI markers.Methods:This cross-sectional analysis included participants from the Three-City Dijon population-based cohort (aged ≥65 years) without dementia, stroke, or history of hospitalized cardiovascular disease, who underwent brain MRI with automated assessment of white matter hyperintensities, visual detection of covert infarcts, and grading of dilated perivascular spaces. Fish intake was assessed through a frequency questionnaire and the primary outcome measure was defined as the first component of a factor analysis of mixed data applied to MRI markers. The association of fish intake with the CVD burden indicator was studied using linear regressions.Results:In total, 1,623 participants (mean age, 72.3 years; 63% women) were included. The first component of factor analysis (32.4% of explained variance) was associated with higher levels of all three MRI markers. Higher fish intake was associated with lower CVD burden. In a model adjusted for total intracranial volume, compared to participants consuming fish <1 per week, those consuming fish 2-3 and ≥4 times per week had a β = -0.19 (95% CI, -0.37; -0.01) and β = -0.30 (-0.57; -0.03) lower indicator of CVD burden, respectively (P trend <0.001). We found evidence of effect modification by age, so that the association of fish to CVD was stronger in younger participants (65-69 years) and not significant in participants aged ≥75 years. For comparison, in the younger age group, consuming fish 2-3 times a week was roughly equivalent (in opposite direction) to the effect of hypertension.Discussion:In this large population-based study, higher frequency of fish intake was associated with lower CVD burden, especially among participants younger than 75 years, suggesting a beneficial effect on brain vascular health before manifestation of overt brain disease.Classification of Evidence:This study provides Class II evidence that in individuals without stroke or dementia, higher fish intake is associated with lower subclinical CVD at MRI.

scholarly journals Ataxia teleangiectasia. Az idegrendszeri érintettség prototípusa primer immundefektusokban

2018 ◽  
Vol 159 (49) ◽  
pp. 2057-2064
Author(s):  
Zoltán Liptai
Keyword(s):  
Immune Deficiency ◽  
Ataxia Telangiectasia ◽  
Late Onset ◽  
Brain Mri ◽  
Cerebellar Atrophy ◽  
Biallelic Mutation ◽  
Pathogenic Variants ◽  
Diagnostic Difficulties ◽  
Immune Deficiencies ◽  
Atm Gene

Abstract: The number of primary immune deficiencies exceeds 350, approximately a quarter of them having neurological implications. Severe central nervous system infections may occur in an even higher proportion. Beyond listing in a table of all diseases with a neurological impact, the author gives detailed analysis of one typical disorder. Ataxia telangiectasia is caused by biallelic mutation of the ATM gene resulting in genomic instability, increased cancer risk, immune deficiency and a predominantly cerebellar neurodegeneration. The most common classic form is characterized by gait and limb ataxia, oculomotor apraxia, choreoathetosis, disturbance of speech and swallowing, less often by other movement disorders. There is no remarkable cognitive deficit. Telangiectasia of the conjunctivae and skin usually appears after 6 years of age. Frequent, especially severe sino-pulmonary infections may indicate the immune deficiency present in 60 to 80% of patients, who are also prone to malignancies. The clinical course is sometimes atypical or has a late onset which results in diagnostic difficulties. Serum alpha-fetoprotein level is elevated in nearly all patients. Brain MRI shows progressive cerebellar atrophy starting at the age of 7–8 years. DNA testing of the ATM gene is necessary for the diagnosis. The detected biallelic pathogenic variants provide help for family planning and for possible gene therapies in the future. Ataxia telangiectasia has to be differentiated from a number of other disorders, some of which also belong to primary immune deficiencies. The disorder has no causal treatment at present, the patients live until their young adult ages. Orv Hetil. 2018; 159(49): 2057–2064.

scholarly journals The Genomic Landscape of Myeloid Neoplasms Evolved from AA/PNH

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 2-2
Author(s):  
Carmelo Gurnari ◽  
Simona Pagliuca ◽  
Bhumika J. Patel ◽  
Hassan Awada ◽  
Cassandra M Kerr ◽  
...  
Keyword(s):  
Immune Escape ◽  
De Novo ◽  
Mutational Analysis ◽  
Germ Line ◽  
Bone Marrow Failure ◽  
Clonal Evolution ◽  
Class I ◽  
Molecular Characteristics ◽  
Cross Sectional ◽  
Tp53 Mutations

Up to 15% of AA patients (pts) treated conservatively with immunosuppression will evolve to myeloid neoplasia (MN), either MDS or AML, over a median time of 10 years regardless of response (0-18 years; n=238). The pathogenesis of MN secondary to AA is diverse and will often include antecedent clonal facilitating events that herald progression. Minor clones have been described in AA, some of which are not contributory to later evolution while other may result in subsequent progression. MDS evolution in inherited bone marrow failure (BMF) syndromes suggests that germ line (GL) alterations can be predisposing. In addition, progression to MN may reflect immune escape due to selection pressure e.g., through acquisition of HLA mutations. Here, we studied the molecular landscape of MN arising from AA, to better understand its pathogenesis and ultimately to develop measures of early detection, prevention, and therapeutic strategies. Among 350 pts diagnosed with AA and PNH, 38 (11%) developed a secondary MN (sMN). Median age at AA/PNH diagnosis was 61 years (15-76). Almost all of pts who underwent transformation (89%) received a 1st line treatment consisting of ATG+CsA in 85% of cases (ORR 59%; 21% CR and 38% PR) and 47% received more than one form of treatment, suggesting a lack/incomplete response or relapse. MDS was the most frequent diagnosis at evolution (77%), followed by AML (21%) and MPN (2%). Myeloid evolution was less common in pts with moderate AA (7% vs 14% in severe) or in the presence of a PNH clone (21% vs. 52% in non-progressors, p=.0003). First we investigated GL alterations classified as Tier1 (9/38 pts) and Tier2 (11/38) based on their pathophysiological impact. Tier1 variants included NF1, CBLC, SBDS (n=2), and SAMD9L and overall were more frequently detected in del(7q) pts (76%, p=.0001). Tier2 included FA variants (BRCA2, FANCI, FANCD2; n=3). Of note, in sMN Tier1 variants were detected in 24% vs. 8% in non-evolved cases (p=.008) and none had concomitant Tier1/Tier2 configuration (0% vs. 9% in non-progressors, p=.05) or GATA2 variants. Cytogenetic abnormalities were most frequent at the time of MN progression in 83% of cases, with chr. 7 alterations present in 47% of cases (-7, 35%; del(7q),12%), followed by complex karyotype (CK, 13%), involving chr.7 in 75% of cases. By comparison, -7/del(7q) are present in 7.5% of cases of our internal cohort of primary MN (p=.0001), but no differences in -7 and del7q distribution were seen. A total of 148 somatic variants (myeloid and HLA panels) were found at the time of evolution in 34/38 sMN pts, with an average of 4.4 mutations/patient. ASXL1 (29% vs 14%, p=.02) and SETBP1 (15% vs 3%, p=.005) hits were more frequent in evolved cases while TET2 and TP53 mutations were less common as compared with pMN. Of note, sMN pts with CK harbored ASXL1 and TP53 mutations in 50% of cases. In a cross-sectional analysis of evolved cases studied at AA onset (n=17) and at myeloid evolution (n=35), somatic lesions in TET2, DNMT3A and ASXL1 genes were found in 5, 1 and 3 pts at baseline, respectively. If variants in TET2 and DNMT3A likely reflect antecedent CHIP, ASXL1 variants may have a role in driving myeloid progression as shown by the higher mutation rate in post AA cases. This hypothesis is further supported by the acquisition of subclonal chr7 abnormalities and by the overall higher clonal burden at sMN onset (median VAF 24% vs 43% respectively, p=.0001). When comparing pts with chr7 abnormalities with de novo counterpart, in sMN genes appeared most commonly mutated in ASXL1 (p=.02), SETBP1 (p=.0007), ETV6 (p=.02) and NF1 (p=.02), while TP53 mutations were less common.The intrinsic peculiarity of this -7/del(7q) sMN subset is also underlined by a different median survival time (12 vs 48 months in sMN vs pMN, respectively, p=.0002). The HLA mutational analysis available for 10 sMN cases showed the presence of somatic class I/II loci variants in 4/10 of progressors, including pts with chr7 abnormalities in 3/4 of cases. Of note, all class I HLA mutations were found in locus C. By comparison, in non-progressing AA pts HLA class I/II variants were found in 13% of pts. Our results demonstrate that AA progression to MN has distinct molecular characteristics. The presence of HLA mutations suggests that immune escape or immune selection may play a role, while the presence of GL predisposition variants shows that they not only may facilitate AA but also clonal evolution as described from classic congenital BMF. Disclosures Patel: Alexion: Other: educational speaker. Voso:Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Carraway:Takeda: Other: Independent Advisory Committe (IRC); ASTEX: Other: Independent Advisory Committe (IRC); Novartis: Consultancy, Speakers Bureau; Abbvie: Other: Independent Advisory Committe (IRC); BMS: Consultancy, Other: Research support, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Stemline: Consultancy, Speakers Bureau. Maciejewski:Alexion, BMS: Speakers Bureau; Novartis, Roche: Consultancy, Honoraria.

scholarly journals GENETIC ANALYSIS OF FAMILIES HAVING AUTOSOMAL RECESSIVE INTELLECTUAL DISABILITY

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
Jamshed Khan ◽  
Muhammad Junaid ◽  
Shahab Uddin ◽  
Khalida Moeed ◽  
Usman Ullah ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Genetic Analysis ◽  
Single Gene ◽  
Cross Sectional Study ◽  
Molecular Diagnostic ◽  
Developmental Defect ◽  
Chromosomal Disorders ◽  
Cross Sectional ◽  
Pathogenic Variants ◽  
Development Delay

Background: Intellectual disability (ID) is a neuro-developmental defect that is manifested by development delay and learning disability. Such defects may be caused due to chromosomal disorders (trisomy 18 or Down syndrome) or single gene mutation. Its worldwide prevalence is estimated to be 1-3%. The genetic etiology of non-syndromic ID is poorly understood. To date, more than 100 loci have been reported to be associated with non-syndromic ID. The objective of this study was to identify the causative genes for three Materials & Methods: This cross-sectional study was conducted in the Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan from March 2014 to August 2015. The inclusion criteria set for the families was consanguineous relation and more than two patients per family (including cousins). All the patients were tested individually in friendly atmosphere using IQ test to scale the ID on the basis of performance. Thereafter, blood samples were taken by aseptic method and DNA was extracted for the purpose of doing genetic analysis. In genetic analysis, exome sequencing was performed to find the pathogenic variants. Subsequently. Sanger sequencing was also done to see the segregation of pathogenic variants. Results: Genetic analysis found mutation in AP4B1 in Family 1, in WDR62 in Family 2, while Family 3 was unremarkable. Conclusion: The study involved genetic analysis of three consanguineous families and found mutation in AP4B1 in Family 1, in WDR62 in Family 2, while Family 3 was unremarkable. The present research will help in devising molecular diagnostic technics for pre-marital and pre-conception testing.

Phenotype Analysis and Genetic Study of Chinese Patients With Treacher Collins Syndrome

2021 ◽  
pp. 105566562110375
Author(s):  
Meng Lu ◽  
Bin Yang ◽  
Zixiang Chen ◽  
Haiyue Jiang ◽  
Bo Pan
Keyword(s):  
Rare Variants ◽  
Clinical Care ◽  
Treacher Collins Syndrome ◽  
Chinese Patients ◽  
Pathogenic Variants ◽  
Premature Termination Codons ◽  
Whole Exome ◽  
Exome Aggregation Consortium ◽  
Phenotype Analysis ◽  
Sporadic Cases

Objective The aim of this study was to confirm the pathogenic variants, explore the genotype–phenotype correlation and characteristics of Chinese patients with Treacher Collins syndrome (TCS). Design Clinical details of 3 TCS family cases and 2 sporadic cases were collected and analyzed. Whole-exome sequencing and Sanger sequencing were conducted to detect causative variants. Setting Tertiary clinical care. Patients This study included 8 patients clinically diagnosed with TCS who were from 3 familial cases and 2 sporadic cases. Main Outcome Measures When filtering the database, variants were saved as rare variants if their frequency were less than 0.005 in the 1000 Genomes Project Database, the Exome Aggregation Consortium (ExAC) browser, and the Novogene database, or they would be removed as common ones. The pathogenic variants identified were verified by polymerase chain reaction. The sequencing results were analyzed by Chromas 2.1 software. Results Two novel pathogenic variants (NM_000356.3: c.537del and NM_000356.3: c.1965_1966dupGG) and 2 known pathogenic variants (NM_000356.3: c.1535del, NM_000356.3: c.4131_4135del) were identified within TCOF1 which are predicted to lead to premature termination codons resulting in a truncated protein. There was a known missense SNP (NM_015972.3: c.139G>A) within POLR1D. No phenotype–genotype correlation was observed. Instead, these 8 patients demonstrated the high genotypic and phenotypic heterogeneity of TCS. Conclusions This study expands on the pathogenic gene pool of Chinese patients with TCS. Besides the great variation among patients which is similar to international reports, Chinese patients have their own characteristics in clinical phenotype and pathogenesis mutations.

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