Liena Elbaghir Omer Elsayed, Norah Ayed AlHarbi, Ashwaq Mohammed Alqarni, Huda Hussein Elwasila Eltayeb, Noura Mostafa Mohamed Mostafa, Maha Mohammed Abdulrahim, Hadeel Ibrahim Bin Zaid, Latifah Mansour Alanzi, Sarah Abdullah Ababtain, Khawlah Aldulaijan, Sheka Yagub Aloyouni, Moneeb Abdullah Kassem Othman, Mohammad Abdullah Alkheilewi, Adel Mohammed Binduraihem, Hadeel Abdollah Alrukban, Hiba Yousif Ahmed, Faten Abdullah AlRadini, Hadil Mohammad Alahdal, Aziza Mufareh Mushiba, Omaima Abdulazeem Alzaher
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引用次数: 0
Abstract
Background: Chromosome 16p11.2 deletions and duplications were found to be the second most common copy number variation (CNV) reported in cases with clinical presentation suggestive of chromosomal syndromes. Chromosome 16p11.2 deletion syndrome shows remarkable phenotypic heterogeneity with a wide variability of presentation extending from normal development and cognition to severe phenotypes. The clinical spectrum ranges from neurocognitive and global developmental delay (GDD), intellectual disability, and language defects (dysarthria /apraxia) to neuropsychiatric and autism spectrum disorders. Other presentations include dysmorphic features, congenital malformations, insulin resistance, and a tendency for obesity. Our study aims to narrow the gap of knowledge in Saudi Arabia and the Middle Eastern and Northern African (MENA) region about genetic disorders, particularly CNV-associated disorders. Despite their rarity, genetic studies in the MENA region revealed high potential with remarkable genetic and phenotypic novelty.
Results: We identified a heterozygous de novo recurrent proximal chromosome 16p11.2 microdeletion by microarray (arr[GRCh38]16p11.2(29555974_30166595)x1) [(arr[GRCh37]16p11.2(29567295_30177916)x1)] and confirmed by whole exome sequencing (arr[GRCh37]16p11.2(29635211_30199850)x1). We report a Saudi girl with severe motor and cognitive disability, myoclonic epilepsy, deafness, and visual impairment carrying the above-described deletion. Our study broadens the known phenotypic spectrum associated with recurrent proximal 16p11.2 microdeletion syndrome to include developmental dysplasia of the hip, optic atrophy, and a flat retina. Notably, the patient exhibited a rare combination of microcephaly, features consistent with the Dandy-Walker spectrum, and a thin corpus callosum (TCC), which are extremely infrequent presentations in patients with the 16p11.2 microdeletion. Additionally, the patient displayed areas of skin and hair hypopigmentation, attributed to a homozygous hypomorphic allele in the TYR gene.
Conclusion: This report expands on the clinical phenotype associated with proximal 16p11.2 microdeletion syndrome, highlighting the potential of genetic research in Saudi Arabia and the MENA region. It underscores the importance of similar future studies.
期刊介绍:
Human Genomics is a peer-reviewed, open access, online journal that focuses on the application of genomic analysis in all aspects of human health and disease, as well as genomic analysis of drug efficacy and safety, and comparative genomics.
Topics covered by the journal include, but are not limited to: pharmacogenomics, genome-wide association studies, genome-wide sequencing, exome sequencing, next-generation deep-sequencing, functional genomics, epigenomics, translational genomics, expression profiling, proteomics, bioinformatics, animal models, statistical genetics, genetic epidemiology, human population genetics and comparative genomics.