Congenital Disorder of Glycosylation: Clinical andMolecular Characteristics of 9 Patients from Turkey

Objective: Congenital defects of glycosylation (CDG) belongs to a group of genetic diseases that lead to impairment in protein, lipid glycosylation and glycosylphosphatidylinositol synthesis. More than 140 types of CDG have been identified and the number is increasing day by day. Since glycosylation is very important for post-translational process and glycosylation is required for half of the proteins in human organism to be able to exert an effect, causes the disease to have an extremely wide clinical spectrum in affected patients. Our aim is to share the clinical features of our patients with CDG and contribute to increase in the awareness of this disease group with highly heterogeneous clinical spectrum.Method: Nine patients from 9 families whose molecular and biochemical diagnosis was confirmed were included in the study. All patients were evaluated by a specialist.in pediatric metabolism Laboratory analysis results and clinical features were obtained from hospital records. Our study presents clinical, biochemical and molecular properties of 9 patients. Results: The patients were detected as having PMM2-CDG (CDG Ia) (n=4), MPI-CDG (CDG Ib) (n=1), ALG3-CDG (CDG Id) (n=1), ALG1-CDG (CDG Ik) (n=1), DOLK-CDG (CDG Im) (n=1) and COG4-CDG (CDG IIj) (n=1). Sialotransferrin electrophoresis could be performed in 8 of 9 patients. Six patients were diagnosed using high- throughout next -generation sequencing technologies. In all of our patients previously indentified variants have been detected. Conclusion: Our study is one of the first CDG case series presented in our country. CDG should be kept in mind as an important preliminary diagnosis in patients with multisystemic involvement and neurological findings.