The First Congenital Disorders of Glycosylation Patient (Fetus) with Homozygous COG5 c.95T>G Variant.

Introduction: Congenital disorders of glycosylation (CDG) are autosomal recessive hereditary genetic disorders characterized by abnormal glycosylation of N-linked oligosaccharides. Case Presentation: In this research, prenatal testing (24th week of pregnancy) revealed findings like polyhydramnios, hydrocephaly, abnormal facial features/shape, brain morphology abnormality, spina bifida, vertebral column abnormality, macrocephaly, scoliosis, micrognathia, abnormal kidney morphology, short fetal femur length, and short fetal humerus length in the fetus. Whole-exome sequencing was performed; the COG5 gene has shown a pathogenic variant. Discussion: Homozygous patients have never been seen before in the literature for COG5-CDG. We demonstrate the first CDG patient at fetus stage with homozygous COG5 c.95T>G variant.