STT3A-CDG is a form of congenital disorders of N-linked glycosylation characterized by developmental delay, intellectual disability, failure to thrive, hypotonia and seizures. STT3A-CDG is caused by mutations in the gene STT3A (11q23.3). The disease is STT3A-congenital disorder of glycosylation (Monarch Disease Ontology id MONDO_0014270). Also known as: CDG syndrome type Iw, CDG-Iw, CDG1W, STT3A-CDG, congenital disorder of glycosylation type 1w, congenital disorder of glycosylation type Iw, congenital disorder of glycosylation, type Iw, autosomal recessive.