scholarly journals Whole exome sequencing reveals a biallelic frameshift mutation in GRXCR2 in hearing impairment in Cameroon

2021 ◽  
Author(s):  
Ambroise Wonkam ◽  
Kamogelo Lebeko ◽  
Shaheen Mowla ◽  
Jean Jacques Noubiap ◽  
Mike Chong ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Hearing Impairment ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
Whole Exome

scholarly journals Whole Exome Sequencing Identifies Three Novel Mutations in the ASPM Gene From Saudi Families Leading to Primary Microcephaly

2021 ◽  
Vol 8 ◽  
Author(s):  
Muhammad Imran Naseer ◽  
Angham Abdulrahman Abdulkareem ◽  
Osama Yousef Muthaffar ◽  
Sameera Sogaty ◽  
Hiba Alkhatabi ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
Genetic Defect ◽  
Deletion Mutation ◽  
Primary Microcephaly ◽  
Novel Mutations ◽  
Whole Exome ◽  
Novel Variants ◽  
Healthy Control

Autosomal recessive primary microcephaly (MCPH) is a neurodevelopmental defect that is characterized by reduced head circumference at birth along with non-progressive intellectual disability. Till date, 25 genes related to MCPH have been reported so far in humans. The ASPM (abnormal spindle-like, microcephaly-associated) gene is among the most frequently mutated MCPH gene. We studied three different families having primary microcephaly from different regions of Saudi Arabia. Whole exome sequencing (WES) and Sanger sequencing were done to identify the genetic defect. Collectively, three novel variants were identified in the ASPM gene from three different primary microcephaly families. Family 1, showed a deletion mutation leading to a frameshift mutation c.1003del. (p.Val335*) in exon 3 of the ASPM gene and family 2, also showed deletion mutation leading to frameshift mutation c.1047del (p.Gln349Hisfs*18), while in family 3, we identified a missense mutation c.5623A>G leading to a change in protein (p.Lys1875Glu) in exon 18 of the ASPM gene underlying the disorder. The identified respective mutations were ruled out in 100 healthy control samples. In conclusion, we found three novel mutations in the ASPM gene in Saudi families that will help to establish a disease database for specified mutations in Saudi population and will further help to identify strategies to tackle primary microcephaly in the kingdom.

scholarly journals Whole exome sequencing identifies rare coding variants in novel human-mouse ortholog genes in African individuals diagnosed with non-syndromic hearing impairment

2020 ◽  
pp. 153537022096038
Author(s):  
Oluwafemi G Oluwole ◽  
Kevin K Esoh ◽  
Edmond Wonkam-Tingang ◽  
Noluthando Manyisa ◽  
Jean Jacques Noubiap ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Hearing Impairment ◽  
Whole Exome Sequencing ◽  
In Silico ◽  
Homozygous Variant ◽  
Whole Exome ◽  
African Populations ◽  
Mouse Orthologs ◽  
Syndromic Hearing Impairment ◽  
Functional Analyses

Physiologically, the human and murine hearing systems are very similar, justifying the extensive use of mice in experimental models for hearing impairment (HI). About 340 murine HI genes have been reported; however, whether variants in all human-mouse ortholog genes contribute to HI has been rarely investigated. In humans, nearly 120 HI genes have been identified to date, with GJB2 and GJB6 variants accounting for half of congenital HI cases, of genetic origin, in populations of European and Asian ancestries, but not in most African populations. The contribution of variants in other known genes of HI among the populations of African ancestry is poorly studied and displays the lowest pick-up rate. We used whole exome sequencing (WES) to investigate pathogenic and likely pathogenic (PLP) variants in 34 novel human-mouse orthologs HI genes, in 40 individuals from Cameroon and South Africa diagnosed with non-syndromic hearing impairment (NSHI), and compared the data to WES data of 129 ethnically matched controls. In addition, protein modeling for selected PLP gene variants, gene enrichment, and network analyses were performed. A total of 4/38 murine genes, d6wsu163e, zfp719, grp152 and minar2, had no human orthologs. WES identified three rare PLP variants in 3/34 human-mouse orthologs genes in three unrelated Cameroonian patients, namely: OCM2, c.227G>C p.(Arg76Thr) and LRGI1, c.1657G>A p.(Gly533Arg) in a heterozygous state, and a PLP variant MCPH1, c.2311C>G p.(Pro771Ala) in a homozygous state. In silico functional analyses suggest that these human-mouse ortholog genes functionally co-expressed interactions with well-established HI genes: GJB2 and GJB6. The study found one homozygous variant in MCPH1, likely to explain HI in one patient, and suggests that human-mouse ortholog variants could contribute to the understanding of the physiology of hearing in humans. Impact statement Despite, human and murine hearing system being very similar, the contribution of variants in relevant mouse-ortholog genes to hearing impairment (HI) has not been fully investigated. The contribution of variants in the known non-syndromic hearing impairment (NSHI) genes among Africans is poorly studied, suggesting that the novel gene(s) and mutations are yet to be discovered in NSHI in the African populations. Using whole exome sequencing (WES), this study identified rare candidate pathogenic and likely pathogenic (PLP) variants in 3/34 novel human-mouse ortholog genes in 3/40 individuals, with one homozygous variant, MCPH1, c.2311C>G p.(Pro771Ala), likely to explain HI in one patient. In silico functional analyses suggest that these human-mouse ortholog genes could contribute to the understanding of the physiology of hearing in humans and thus the variants identified in those genes deserve additional investigations.

scholarly journals A Novel De Novo Frameshift Mutation in KAT6A Identified by Whole Exome Sequencing

2018 ◽  
Vol 08 (01) ◽  
pp. 010-014 ◽  
Author(s):  
Wafa Alazaizeh ◽  
Asem Alkhateeb
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Brain Magnetic Resonance Imaging ◽  
Comparative Genomic ◽  
Feeding Difficulties ◽  
Whole Exome

AbstractIntellectual disability is a common condition with multiple etiologies. The number of monogenic causes has increased steadily in recent years due to the implementation of next generation sequencing. Here, we describe a 2-year-old boy with global developmental delay and intellectual disability. The child had feeding difficulties since birth. He had delayed motor skills and muscular hypotonia. Brain magnetic resonance imaging revealed diffuse white matter loss and thinning of the corpus callosum. Banded karyotype and comparative genomic hybridization (CGH) array were normal. Whole exome sequencing revealed a novel de novo frameshift mutation c.3390delA (p.Lys1130Asnfs*4) in KAT6A gene (NM_006766.4). The heterozygous mutation was confirmed by Sanger sequencing in the patient and its absence in his parents. KAT6A that encodes a histone acetyltransferase has been recently found to be associated with a neurodevelopmental disorder autosomal dominant mental retardation 32 (OMIM: no. 616268). Features of this disorder are nonspecific, which makes it difficult to characterize the condition based on the clinical symptoms alone. Therefore, our findings confirm the utility of whole exome sequencing to quickly and reliably identify the etiology of such conditions.

scholarly journals Whole-Exome Sequencing Identified a Novel Homozygous Frameshift Mutation of HPS3 in a Consanguineous Family with Hermansky-Pudlak Syndrome

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zhao-Xia Wang ◽  
Yi-Hui Liu ◽  
Yi Dong ◽  
Ya-Li Li ◽  
Tie-Yu Tang ◽  
...  
Keyword(s):  
Visual Impairment ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
Novel Mutation ◽  
Bleeding Diathesis ◽  
Consanguineous Family ◽  
Whole Exome ◽  
The Family ◽  
Hermansky Pudlak Syndrome

Hermansky-Pudlak syndrome (HPS) is a rare genetic disorder with an autosomal recessive inherited pattern. It is mainly characterized by deficiencies in lysosome-related organelles, such as melanosomes and platelet-dense granules, and leads to albinism, visual impairment, nystagmus, and bleeding diathesis. A small number of patients will present with granulomatous colitis or fatal pulmonary fibrosis. At present, mutations in ten known genetic loci (HPS1–11) have been identified to be the genetic cause of HPS. In this study, we enrolled a consanguineous family who presented with typical HPS phenotypes, such as albinism, visual impairment, nystagmus, and bleeding diathesis. Whole-exome sequencing and Sanger sequencing were applied to explore the genetic lesions of the patient. A novel homozygous frameshift mutation (NM_032383.5, c.1231dupG/p.Aps411GlyfsTer32) of HPS3 was identified and cosegregated in the family members. Furthermore, real-time PCR confirmed that the mutation decreased the expression of HPS3, which has been identified as the disease-causing gene of HPS type 3. According to ACMG guidelines, the novel mutation, resulting in a premature stop codon at amino acid 442, is a pathogenic variant. In summary, we identified a novel mutation (NM_032383.5, c.1231dupG/p.Aps411GlyfsTer32) of HPS3 in a family with HPS. Our study expanded the variant spectrum of the HPS3 gene and contributed to genetic counseling and prenatal genetic diagnosis of the family.

scholarly journals A Novel Frameshift Mutation in KAT6A Is Associated with Pancraniosynostosis

2020 ◽  
Author(s):  
Fady P. Marji ◽  
Jennifer A. Hall ◽  
Erin Anstadt ◽  
Suneeta Madan-Khetarpal ◽  
Jesse A. Goldstein ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
De Novo ◽  
Cranial Sutures ◽  
Speech Delay ◽  
First Case ◽  
Whole Exome ◽  
Suture Fusion

AbstractDe novo heterozygous mutations in the KAT6A gene give rise to a distinct intellectual disability syndrome, with features including speech delay, cardiac anomalies, craniofacial dysmorphisms, and craniosynostosis. Here, we reported a 16-year-old girl with a novel pathogenic variant of the KAT6A gene. She is the first case to possess pancraniosynostosis, a rare suture fusion pattern, affecting all her major cranial sutures. The diagnosis of KAT6A syndrome is established via recognition of its inherent phenotypic features and the utilization of whole exome sequencing. Thorough craniofacial evaluation is imperative, craniosynostosis may require operative intervention, the delay of which may be detrimental.

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