<h4>Background</h4>Congenital disorders of glycosylation type Iy (SSR4-CDG, CDG1Y) is an ultra-rare X-linked disorder caused by pathogenic variants in the <i>SSR4</i> gene, encoding a subunit of the translocon-associated protein (TRAP) complex. The gene discussed is SSR4; the disease is congenital disorder of glycosylation type II.