Nicolaides-Baraitser syndrome is a condition that affects many body systems. Affected individuals can have a wide variety of signs and symptoms, but the most common are sparse scalp hair, small head size (microcephaly), distinct facial features, short stature, prominent finger joints, unusually short fingers and toes (brachydactyly), recurrent seizures (epilepsy), and moderate to severe intellectual disability with impaired language development.

Nicolaides-Baraitser syndrome is caused by mutations in the SMARCA2 gene. This gene provides instructions for making one piece (subunit) of a group of similar protein complexes known as SWI/SNF complexes. These complexes regulate gene activity (expression) by a process known as chromatin remodeling. Chromatin is the network of DNA and proteins that packages DNA into chromosomes. The structure of chromatin can be changed (remodeled) to alter how tightly DNA is packaged. Chromatin remodeling is one way gene expression is regulated during development; when DNA is tightly packed, gene expression is lower than when DNA is loosely packed. To provide energy for chromatin remodeling, the SMARCA2 protein uses a molecule called ATP.

Nicolaides-Baraitser syndrome is likely a rare condition; approximately 75 cases have been reported in the scientific literature.

Nicolaides-Baraitser syndrome follows an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Published Date: December 01, 2015
Published By: National Institutes of Health