scholarly journals A Homozygous Mutation in GPT2 Associated with Nonsyndromic Intellectual Disability in a Consanguineous Family from Costa Rica

2017 ◽  
pp. 59-66 ◽  
Author(s):  
Tanya Lobo-Prada ◽  
Heinrich Sticht ◽  
Sixto Bogantes-Ledezma ◽  
Arif Ekici ◽  
Steffen Uebe ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohd Fareed ◽  
Vikas Makkar ◽  
Ravi Angral ◽  
Mohammad Afzal ◽  
Gurdarshan Singh

AbstractNephrotic syndrome arising from monogenic mutations differs substantially from acquired ones in their clinical prognosis, progression, and disease management. Several pathogenic mutations in the COQ8B gene are known to cause nephrotic syndrome. Here, we used the whole-exome sequencing (WES) technology to decipher the genetic cause of nephrotic syndrome (CKD stage-V) in a large affected consanguineous family. Our study exposed a novel missense homozygous mutation NC_000019.9:g.41209497C > T; NM_024876.4:c.748G > A; NP_079152.3:p.(Asp250Asn) in the 9th exon of the COQ8B gene, co-segregated well with the disease phenotype. Our study provides the first insight into this homozygous condition, which has not been previously reported in 1000Genome, ClinVar, ExAC, and genomAD databases. In addition to the pathogenic COQ8B variant, the WES data also revealed some novel and recurrent mutations in the GLA, NUP107, COQ2, COQ6, COQ7 and COQ9 genes. The novel variants observed in this study have been submitted to the ClinVar database and are publicly available online with the accessions: SCV001451361.1, SCV001451725.1 and SCV001451724.1. Based on the patient's clinical history and genomic data with in silico validation, we conclude that pathogenic mutation in the COQ8B gene was causing kidney failure in an autosomal recessive manner. We recommend WES technology for genetic testing in such a consanguineous family to not only prevent the future generation, but early detection can help in disease management and therapeutic interventions.



2013 ◽  
Vol 85 (4) ◽  
pp. 390-392
Author(s):  
S. Dad ◽  
E. Østergaard ◽  
K.A. Wadt ◽  
J. Lunding ◽  
H. Eiberg ◽  
...  


2013 ◽  
Vol 86 (3) ◽  
pp. 276-281 ◽  
Author(s):  
L. Roos ◽  
M. Fang ◽  
C. Dali ◽  
H. Jensen ◽  
N. Christoffersen ◽  
...  


2020 ◽  
Author(s):  
Chia-Hsiang Chen ◽  
Yu-Shu Huang ◽  
Ting-Hsuan Fang

Abstract Background: The human LINS1 gene is located at 15q26.3 and encodes the lines homolog 1 protein that contains the Drosophila lines homologous domain. Mutations in the LINS1 gene have been reported to cause a rare recessive form of intellectual disability. A total of seven mutations in six studies have been reported in the literature to our knowledge. Results: Using whole genome sequencing analysis, we identified a novel homozygous nonsense mutation in the LINS1 gene in these two sisters who presented moderate intellectual disability, schizophrenia symptoms, and severe anxiety. The mutation was a C-to-T substitution at the cDNA nucleotide position 274 that changed the amino acid glutamine at the codon 92 to stop codon (Gln92X), resulting in the truncation of LINS1 protein after amino acid 91. This mutation was transmitted from their unrelated parents who were heterozygous carriers. Conclusions: Our findings not only add to the allelic heterogeneity of the LINS1-associated intellectual disability but also expand the spectrum of clinical phenotypes of patients with LINS1 mutations. Our study suggests that the human LINS1 gene mutation may play a role in the pathogenesis of psychosis and anxiety in addition to the intellectual disability.



Author(s):  
Г.Е. Руденская ◽  
В.А. Кадникова ◽  
А.Л. Чухрова ◽  
Т.В. Маркова ◽  
О.П. Рыжкова

Актуальность. Наследственные спастические параплегии (НСП) - одна из наиболее гетерогенных групп наследственных нервных болезней, насчитывающая около 80 клинико-генетических форм (SPG) с хронологической нумерацией. Методы высокопроизводительного экзомного секвенирования (MPS) принципиально расширили возможности выделения новых SPG и практической ДНК-диагностики. В ФГБНУ МГНЦ проводится первое в России комплексное клинико-молекулярное исследование НСП на основе MPS и ряда дополнительных методов ДНК-анализа. Группа верифицированных случаев насчитывает 114 семей с 20 различными формами, включая редкие аутосомно-рецессивные (АР) формы, мало известные генетикам и неврологам. Цель: представить первые российские наблюдения редких АР форм: SPG5, SPG26, SPG35 и SPG39, связанных соответственно с генами CYP7B1, B4GALNT1, FA2H и PNPLA6, участвующими в разных звеньях липидного обмена. Методы. Первичная группа включала около 200 российских семей с предварительным клиническим диагнозом НСП или сходных болезней; основная группа: 114 семей с диагностированной формой SPG; материал статьи: 4 семьи. Использованы методы: клинико-генеалогический, кастомная MPS-панель «параплегии» (64 гена); секвенирование по Сэнгеру; мультиплексная-лигаза зависимая амплификация MLPA (выборочно); полноэкзомное секвенирование WES (выборочно); биоинформатический анализ. Результаты: подгруппа АР SPG включила 22 семьи/12 форм. Представленные 4 формы выявлены в единичных семьях. SPG5: подросток 17 лет в русской семье; начало в 15 лет, умеренный спастический парапарез, легкая сопутствующая атаксия. Генотип CYP7B1: ранее описанные мутации с.334С>T (p.Arg112Ter)/c.1190C>T (p.Pro397Leu) у больного и здоровой сестры 8 лет (доклиническая стадия), родители - гетерозиготные носители. SPG26: мальчик 13 лет в неинбредной русской семье; начало в раннем детстве, медленно прогрессирующий спастический парапарез, дизартрия, когнитивные и поведенческие нарушения, нормальная МРТ. Генотип B4GALNT1: новая мутация c.1514G>C (p.Arg505Pro) в гомозиготном состоянии у больного, в гетерозиготном - у родителей. Случай SPG26 - 14-й описанный в мире, гомозиготность по мутации, вызывающей очень редкую форму SPG, в неинбредной русской семье необычна. SPG35: мальчик 5 лет в этнически смешанной семье (мать русская, отец татарско-бурятского происхождения) из Сибири; начало в 4 года, быстро прогрессирующий спастический парапарез без других симптомов, нормальная МРТ. Генотип FA2H: ранее описанная мутация с.805С>T (p.Arg269Cys) и новая мутация c.106C>T (p.Leu36Phe). SPG39: мальчик 10 лет в русско-татарской семье; начало в 5 лет, умеренный спастический парапарез без других симптомов. Генотип PNPLA6: описанная ранее интронная мутация с.199-2A>T / новая мутация c.2033G>A (p.Gly678Asp), родители - гетерозиготные носители. Выводы. НСП у российских больных представлены широким спектром клинико-генетических форм, включая редкие АР SPG в неинбредных русских и в этнически смешанных семьях. Cлучаи SPG5, SPG26, SPG35 и SPG39 - первые российские описания. Из найденных в 4 генах 7 мутаций три ранее не описаны. MPS - метод выбора ДНК-диагностики болезней с выраженной генетической гетерогенностью, таких, как НСП. Objective: hereditary spastic paraplegias (HSP) are a heterogeneous group including about 80 forms: SPGs (Spastic Paraplegia Gene) numbered chronologically. Massive parallel sequencing MPS greatly improved possibilities of new SPGs disclosure and of practical DNA diagnostics. First Russian HSP complex investigation of HSP using MPS is being performed in FSBI PCMG. By now, the group of genetically diagnosed cases numbers 114 families with 20 different SPGs, including rare autosomal recessive forms poorly known to geneticists and neurologists. Aim: to present first Russian cases of rare autosomal recessive (AR) forms: SPG5, SPG26, SPG35, and SPG39. The genes, CYP7B1, B4GALNT1, FA2H, and FA2H correspondingly, are involved in lipid metabolism. Materials: initial group: about 200 Russian families with preliminary clinical diagnosis of HSP or alike disorders; index group: 114 SPG-confirmed families; paper material: the four families. Methods: clinical investigation, genealogical analysis; molecular methods: custom MPS-panel “paraplegias” (63 genes), Sanger sequencing, multiplex ligation-dependent probe amplification MLPA (selectively), whole-exome sequencing WES (selectively); bioinformatic analysis. Results. Subgroup of AR SPG included 22 families/12 forms. SPG5, 26, 35, 39 were detected in single families. SPG5: a 17-year-old youth in a Russian family; onset in 15 years, moderate spastic paraparesis, mild ataxia; CYP7B1 genotype: two earlier reported mutations .334С>T (p.Arg112Ter) и c.1190C>T (p.Pro397Leu) in the patient and in unaffected younger sister (preclinical stage), parents - heterozygous carries. SPG26: a 13-year old boy in a Russian non-consanguineous family; early-childhood onset, slowly progressing paraparesis, dysarthria, cognitive and behavioral impairment; B4GALNT1 genotype: novel homozygous mutation c.1514G>C (p.Arg505Pro) in the boy, heterozygosity in parents; homozygosity for a very rare gene (14th SPG26 world case) in a Russian non-consanguineous family is unusual. SPG35: a 5-year-old boy in a Sibirian ethnically mixed family (Russian mother, father of Tatar-Buryat ethnicity); onset in 4 years, rapidly progressing paraparesis with no other signs, normal MRI; FA2H genotype: reported earlier с.805С>T (p.Arg269Cys) / novel c.106C>T (p.Leu36Phe). SPG39: a 10-year-old boy in a Russian-Tatar family; onset in 5 years, slowly progressing paraparesis with no other signs; PNPLA6 genotype: reported earlier intronic с.199-2A>T novel c.2033G>A (p.Gly678Asp), parents - heterozygous carriers. Conclusions. HSP in Russian patients present a wide spectrum including rare AR SPG in non-consanguineous Russian families and in families of mixed ethnicity. Our SPG5, SPG26, SPG35 and SPG39 cases are first in Russia; of 7 mutations detected in the 4 genes 3 mutations were novel. MPS is method of choice in DNA diagnostics of heterogeneous disorders like HSP.



2019 ◽  
Vol 84 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Ronggui Qu ◽  
Qing Sang ◽  
Xueqian Wang ◽  
Yao Xu ◽  
Biaobang Chen ◽  
...  


Author(s):  
Afsaneh BAZGIR ◽  
Mehdi AGHA GHOLIZADEH ◽  
Faezeh SARVAR ◽  
Zahra PAKZAD

Autosomal recessive primary microcephaly (MCPH) is a rare genetic disorder, leading to the defect of neurogenic brain development. Individuals with MCPH reveal reduced head circumference and intellectual disability. Several MCPH loci have been identified from several populations. Genetic heterogeneity of this disorder represents molecular testing challenge. An 8 yr old female, born from consanguineous parents, was attended to Fardis Central Lab, Alborz, Iran. Based on the reduced circumference and intellectual disability, MCPH was diagnosed. Whole exome sequencing of the patient identified a novel homozygous frameshift mutation (c.2738dupT, p.Cys914fs) in exon 9 Abnormal Spindle-like Microcephaly )ASPM( gene. By Sanger sequencing, segregation analysis showed that both parents were heterozygous carriers for this variant. The novel frameshift mutation likely truncates the protein, resulting in loss of normal function ASPM in homozygous mutation carriers. The study might add a new pathogenic variant in mutations of the ASPM gene as a causative variant in patients with MCPH and might be helpful in genetic counseling of consanguineous families.



2020 ◽  
Vol 8 (1) ◽  
pp. e001601 ◽  
Author(s):  
Hu Lin ◽  
Xuelian Zhou ◽  
Xuefeng Chen ◽  
Ke Huang ◽  
Wei Wu ◽  
...  

IntroductionLoss-of-function mutations in tRNA methyltransferase 10 homologue A (TRMT10A), a tRNA methyltransferase, have recently been described as a monogenic cause of early-onset diabetes with microcephaly, epilepsy and intellectual disability.Research design and methodsWe report a Chinese young patient who was diagnosed with diabetes mellitus as a result of a TRMT10A mutation.ResultsA homozygous mutation c.496–1G>A in TRMT10A was identified using targeted next-generation sequencing and confirmed by PCR/Sanger sequencing. In addition to being diagnosed with diabetes, the patient also has microcephaly and intellectual deficiency. The diabetes was due to marked insulin resistance and responded very well to metformin treatment.ConclusionOur case is the first report in the Asian population. It adds to current knowledge of TRMT10A related with young-onset non-insulin-dependent diabetes and confirms the a single previous report of insulin resistance in this syndrome. Genomic testing should be considered in children with non-insulin-dependent diabetes with intellectual disability and microcephaly. A clear genetic diagnosis is helpful for early detection and treatment addressing insulin resistance.



2015 ◽  
Vol 167 (8) ◽  
pp. 1913-1915 ◽  
Author(s):  
Sander Pajusalu ◽  
Tiia Reimand ◽  
Katrin Õunap


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