Congenital Disorder of Glycosylation Type II with COG6 Gene Mutation: A Rare Case of Shaheen Syndrome in Qatar

Export Congenital disorders of glycosylation (CDG) represent a group of diseases characterized by impaired synthesis of glycans in glycoproteins and glycolipids. This case report presents the clinical findings of a 4-year-old Qatari boy with Shaheen syndrome, a less severe variant of CDG associated with COG6 gene mutations. The patient exhibited developmental delays, dysmorphic features, and systemic manifestations, including dacryostenosis. Whole exome sequencing revealed a homozygous pathogenic variant in the COG6 gene. The COG complex, to which COG6 belongs, plays a crucial role in maintaining Golgi apparatus function and glycosylation processes. This case contributes to the growing understanding of COG6-related disorders and highlights the need for further research to understand the observed variations in transferrin isoelectric focusing patterns among individuals with the same genetic disorder. Additionally, the presence of dacryostenosis in this patient emphasizes the importance of exploring associated risk factors and refining diagnostic and treatment approaches for lacrimal duct obstruction. We report the first case of Shaheen syndrome in the State of Qatar, and the twentieth case worldwide to the best of our knowledge.