CHIME syndrome [OMIM #280000], also known as Zunich neuroectodermal syndrome, is a rare multisystemic disorder characterized by Colobomas, Heart defects, Ichthyosiform dermatosis, Mental retardation and Ear anomalies. Affected individuals typically have distinctive facial features, which include hypertelorism, brachycephaly, epicanthal folds and a broad nasal root. Other clinical findings include abnormal growth, genitourinary abnormalities, seizures, and feeding difficulties.
Ng et al. (2012) identified compound heterozygous mutations in the PIGL gene (phosphatidylinositol glycan, class L) [OMIM #605947] in 6/6 (100%) patients with a clinical diagnosis of CHIME syndrome. To date, mutations identified by sequencing have included frameshift, nonsense, splice site and missense mutations. PIGL has 7 coding exons and is located at 17p11.2. The PIGL gene codes for an enzyme which localizes to the endoplasmic reticulum and is involved in the glycosylphosphatidylinositol (GPI) biosynthesis pathway.