PMM2-CDG and nephrotic syndrome: A case report.

Congenital disorders of glycosylation (CDG) are a group of rare metabolic diseases, characterized by a defect in the protein glycosylation process. Enzymes involved in this metabolic mechanism have ubiquitous distribution; thus, their alteration can cause systemic involvement and considerable phenotypic variability. Nephrotic syndrome (NS) is a clinical condition characterized by edema, hypoalbuminemia, hyperlipidemia, and proteinuria. We hereby report the case of a girl with central hypotonia, epilepsy, and severe psychomotor delay diagnosed with phosphomannomutase 2 deficiency (PMM2-CDG) after presenting with nephrotic syndrome at age 4 years.