scholarly journals Clinical and Molecular Update on the Fourth Reported Family with Hamamy Syndrome

2021 ◽  
pp. 1-9
Author(s):  
André Mégarbané ◽  
Sayeeda Hana ◽  
Hala Mégarbané ◽  
Christel Castro ◽  
Sylvain Baulande ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Missense Mutation ◽  
Whole Exome Sequencing ◽  
Bone Fragility ◽  
Dentinogenesis Imperfecta ◽  
Review Of The Literature ◽  
Obligate Carrier ◽  
Whole Exome ◽  
Sequencing Studies

We report on 2 cousins, a girl and a boy, born to first-cousin Lebanese parents with Hamamy syndrome, exhibiting developmental delay, intellectual disability, severe telecanthus, abnormal ears, dentinogenesis imperfecta, and bone fragility. Whole-exome sequencing studies performed on the 2 affected individuals and one obligate carrier revealed the presence of a homozygous c.503G&#x3e;A (p.Arg168His) missense mutation in <i>IRX5</i> in both sibs, not reported in any other family. Review of the literature and differential diagnoses are discussed.

scholarly journals Whole Exome Sequencing Identifies a Novel COL1A1 Missense Mutation Causing Dentinogenesis Imperfecta Type I Without Skeletal Abnormalities

2021 ◽  
Author(s):  
Yuting Zeng ◽  
Yuhua Pan ◽  
Jiayao Mo ◽  
Zhiting Ling ◽  
Lifang Jiang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Missense Mutation ◽  
Whole Exome Sequencing ◽  
Blue Staining ◽  
Nanoindentation Test ◽  
Type I ◽  
Dentinogenesis Imperfecta ◽  
Whole Exome ◽  
Blue Sclerae ◽  
The Impact

Abstract Background：Osteogenesis imperfecta (OI) is a genetic disorder characterized by bone fragility, blue sclerae and dentinogenesis imperfecta (DGI), which are mainly caused by a mutation of the COL1A1 or COL1A2 genes that encode type I procollagen.Methods: The ultrastructure of dentin was analyzed by micro-CT, scanning electron microscopy, energy-dispersive spectroscopy analysis, nanoindentation test and Toluidine Blue Staining. Whole-exome sequencing (WES) was performed to identify the pathogenic gene. The function of the mutant COL1A1 was studied by real-time PCR, western blotting, subcellular localization. Functional analysis in dental pulp stem cells (DPSCs) was also performed to explore the impact of the identified mutation on this phenotype. Results: WES identified a missense mutation (c.1463G > C) in exon 22 of the COL1A1 gene. However, the cases reported herein only exhibited DGI-I in the clinical phenotype, there is no bone disease and any other common abnormal symptom caused by COL1A1 mutation. In addition, ultrastructural analysis of the tooth affected with non-syndromic DGI-I showed that the abnormal dentin was accompanied by disruption of odontoblast polarization, reduced numbers of odontoblasts, loss of dentinal tubules, and reduction in hardness and elasticity, suggesting severe developmental disturbance. What’s more, the odontoblast differentiation ability based on DPSCs that were isolated and cultured from the DGI-I patient was enhanced compared with those from an age-matched, healthy control.Conclusion: This study helped the family members to understand the disease progression and provided new insights into the phenotype-genotype association in collagen-associated diseases and improve clinical diagnosis of OI/DGI-I.

scholarly journals Whole exome sequencing identifies a novel mutation in spermine synthase gene (SMS) associated with Snyder-Robinson Syndrome

2020 ◽  
Author(s):  
Talal J. Qazi ◽  
Qiao Wu ◽  
Ailikemu Aierken ◽  
Daru Lu ◽  
Ihtisham Bukhari ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Missense Mutation ◽  
Whole Exome Sequencing ◽  
Mutational Analysis ◽  
Novel Mutation ◽  
Facial Dysmorphism ◽  
Clinical Genetic ◽  
Spermine Synthase ◽  
Whole Exome

Abstract Background: Mutations in the spermine synthase (SMS) gene have been reported to cause a rare x-linked intellectual disability known as Snyder-Robinson Syndrome (SRS). Besides intellectual disability, SRS is also characterized by reduced bone density, bone deformities, osteoporosis and facial dysmorphism. SRS phenotypes evolve with age from childhood to adulthood. Methods: Whole exome sequencing was performed to know the causative gene/mutation. Later we confirmed the mutation through sanger sequencing. Furthermore, we also performed the mutational analysis through HOPE SERVER and SWISS-MODEL. Also, radiographs were also obtained for affected individual to confirm the disease features. Results: In this article, we report the first Pakistani family consisting of three patients with SRS and a novel missense mutation in the SMS gene (c.905C >T: p.S302L). In addition to the typical phenotypes, one patient presented with epilepsy from an early age that was characterized by generalized seizures. The clinical, genetic and in-silico analysis, review of the literature links the affected patients of the family with Snyder-Robinson syndrome and mutation affects the spermine synthase activityConclusion: A novel missense mutation in the SMS gene (c.905C >T: p.S302L) causing Snyder-Robinson Syndrome (SRS) reported in Pakistan Family.

RHOBTB2 p.Arg511Trp Mutation in Early Infantile Epileptic Encephalopathy-64: Review and Case Report

2021 ◽  
Author(s):  
J Fonseca ◽  
C Melo ◽  
C Ferreira ◽  
M Sampaio ◽  
R Sousa ◽  
...  
Keyword(s):  
Case Report ◽  
Intellectual Disability ◽  
Status Epilepticus ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Epileptic Encephalopathy ◽  
Btb Domain ◽  
Pathogenic Variants ◽  
Severe Intellectual Disability ◽  
Whole Exome

AbstractEarly infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 (RHOBTB2) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.

scholarly journals Whole exome sequencing identified a novel missense mutation in EPM2A underlying Lafora disease in a Pakistani family

Seizure ◽  
2017 ◽  
Vol 51 ◽  
pp. 200-203
Author(s):  
Zain Aslam ◽  
Eungi Lee ◽  
Mazhar Badshah ◽  
Muhammad Naeem ◽  
Changsoo Kang
Keyword(s):  
Exome Sequencing ◽  
Missense Mutation ◽  
Whole Exome Sequencing ◽  
Pakistani Family ◽  
Lafora Disease ◽  
Whole Exome

scholarly journals Whole exome sequencing identifies a novel mutation in ASPM and ultra-rare mutation in CDK5RAP2 causing Primary microcephaly in consanguineous Pakistani families

2021 ◽  
Vol 38 (1) ◽  
Author(s):  
Ehtisham ul Haq Makhdoom ◽  
Haseeb Anwar ◽  
Shahid Mahmood Baig ◽  
Ghulam Hussain
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Novel Mutation ◽  
Speech Impairment ◽  
Primary Microcephaly ◽  
Rare Mutation ◽  
Homozygous Variant ◽  
Whole Exome ◽  
Pakistani Families

Background & Objectives: Primary Microcephaly (MCPH) is a rare neurogenetic disease, manifesting congenitally reduced head circumference and non-progressive intellectual disability (ID). To date, twenty-eight genes with biallelic mutations have been reported for this disorder. The study aimed for molecular genetic characterization of Pakistani families segregating MCPH. Methods: We studied two unrelated consanguineous families (family A and B) presenting >2 patients with diagnostic symptoms of MCPH, born to asymptomatic parents. We employed whole-exome sequencing (WES) of probands to find putative causal mutations. The candidate variants were further confirmed and analyzed for co-segregation by Sanger sequencing of all available members of each family. This study was conducted at Government College University, Faisalabad, Pakistan, and Cologne Center for Genomics (CCG), University of Cologne, Germany; during 2017-2020. Results: We identified a novel homozygous variant c.10097_10098delGA, p.(Gly3366Glufs*19) in exon 26 of ASPM gene in family A which presents with moderate intellectual disability, speech impairment, visual abnormalities, seizures, and ptyalism. Family B was found to segregate nonsense, homozygous variant c.448C>T p.(Arg150*) in CDK5RAP2. The patients also exhibited mild to severe seizures without ptyalism that has not been previously reported in patients with mutations in the CDK5RAP2 gene. Conclusion: We report a novel mutation in ASPM and ultra-rare mutation in the CDK5RAP2 gene, both causing primary microcephaly. The study expands the mutational spectrum of the ASPM gene to 212, and also adds to the clinical spectrum of CDK5RAP2 mutations. It also demonstrated the utility of WES in the investigation and genetic diagnosis of genetically heterogeneous disorders like MCPH. These findings would aid in diagnostic and preventive strategies including carrier screening, cascade testing, and genetic counselling. doi: https://doi.org/10.12669/pjms.38.1.4464 How to cite this:Makhdoom EH, Anwar H, Baig SM, Hussain G. Whole exome sequencing identifies a novel mutation in ASPM and ultra-rare mutation in CDK5RAP2 causing Primary microcephaly in consanguineous Pakistani families. Pak J Med Sci. 2022;38(1):---------.  doi: https://doi.org/10.12669/pjms.38.1.4464 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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