SLC33A1 and Global developmental delay: A missense mutation, p.Arg163Trp, in CCS domain II along with a homozygous mutation (p.Tyr366*) in SLC33A1 gene is reported to cause severe muscular hypotonia, hypoglycemia, pericardial effusion, developmental regression, epilepsy, congenital cataracts, bilateral hearing loss, developmental delay, cerebral palsy and very low serum Cu and ceruloplasmin levels in a Turkish patient [25].