Clinical and molecular features of congenital disorder of glycosylation in patients with type 1 sialotransferrin pattern and diverse ethnic origins

Objective: To increase awareness of congenital disorders of glycosylation (CDG), we report the features of patients with a variety of clinical presentations ranging from mild hypotonia and strabismus to severe neurologic impairment. Study design: Nine North American patients with CDC type I and different ethnic origins were studied. Results: All patients had transferrin isoelectric focusing studies with a type I sialotransferrin pattern. Molecular analysis showed the previously described R141 H, V231M, and T237M PMM2 mutations in four patients as well as 3 rare mutations (DeltaC389, L104V, and IVSI -1 G --> A) in the PMM2 gene in two Asian patients. Conclusions: The clinical features of these patients with diverse ethnic backgrounds confirm the variable course of CDC type I. Screening for CDC should be considered in children with relatively mild neurologic impairment, especially if they have suggestive Findings such as cerebellar hypoplasia and abnormal fat distribution.