Abstract
Anophthalmia is the most severe ocular malformation inherited in an autosomal, X-linked, recessive, or dominant form. We report here the use of whole exome sequencing (WES) to help the clinical diagnosis of familial anophthalmia in Harare, Zimbabwe. A mother presented her two sons, who are half-brothers, at the Eye, Ear, Nose, and Throat Institute, Ophthalmology Unit in Harare, Zimbabwe. Upon clinical examination, half-brothers were diagnosed with clinical bilateral anophthalmia. The mother requested a genetic diagnosis for her two sons. To segregate the phenotype with genotype, whole blood was collected from two half-brothers, their mother, maternal aunt, and maternal uncle to the half-brothers, and an unrelated healthy control. Genetic characterization was done, first, through a candidate gene approach screening of putative genes SOX2, OTX2, VSX2, PAX6, and RAX. When no causative variants were identified, the next step employed WES. Variants in 80 genes associated with anophthalmia were prioritized and subjected to pathogenicity testing. One pathogenic variant, BCOR c.254C>T (rs121434618, p. Pro85Leu), segregated with the mother and her two sons. The present clinical genomics study of a family and a healthy control sample underscores WES as a valuable tool that can help clinical diagnosis of anophthalmia in the Zimbabwean clinical setting. In this article, we also offer a reasoned discussion and call from the field, to fund clinical genomics and omics research and development in planetary health, especially in the current era of uncertainties in international aid and funding of innovative technologies. The findings reported herein encourage further research on the clinical utility of WES as a diagnostic tool in Africa and around the world as well, given that the candidate gene approach might miss the important genes or variants of relevance to disease pathophysiology.
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