Congenital Disorder of Glycosylation: Clinical and Molecular Characteristics of 9 Patients from Turkey

INTRODUCTION: Congenital disorders of glycosylation (CDG) is a group of genetic diseases that lead to impairment in protein and lipid glycosylation and glycosylphosphatidylinositol synthesis. More than 140 types of CDG have been identified and the number is increasing day by day. Glycosylation is very important in post-translational process and half of the proteins in human organism require glycosylation in order to exert an effect. Therefore, the disease causes an extremely wide clinical spectrum in affected patients. Our aim is to share the clinical features of our patients with CDG and contributing to increase the awareness of this highly heterogeneous clinical spectrum among paediatricians. METHODS: Nine patients from 9 families whose molecular and biochemical diagnosis was confirmed were included in the study. All patients were evaluated by a pediatric metabolism specialist. Laboratory analysis results and clinical features were obtained from hospital records. Clinical, biochemical and molecular properties of 9 patients were reported in this present study. RESULTS: Four patients were detected as PMM2-CDG (CDG Ia), 1 patient MPI-CDG (CDG Ib), 1 patient ALG3-CDG (CDG Id), 1 patient ALG1-CDG (CDG Ik), 1 patient DOLK-CDG (CDG Im) and 1 patient COG4-CDG (CDG IIj). Sialotransferrin Electrophoresis was performed in 8 of of 9 patients. Six patients were diagnosed by high output next generation sequencing technologies. All of our patients had previously indentified variants DISCUSSION AND CONCLUSION: This study is one of the first CDG case series presented in this country. CDG should be kept in mind as an important preliminary diagnosis in patients with multi-systemic involvement and neurological findings.