Nicolaides-Baraitser syndrome: two new cases with autism spectrum disorder.

Nicolaides-Baraitser syndrome is a rare clinical condition characterized by mental retardation with impairment of expressive language, short stature, microcephaly, sparse hair, typical facial dysmorphisms, and interphalangeal joint swellings. To date 24 cases have been reported, most of them being sporadic. The genetic background of Nicolaides-Baraitser syndrome is unclear in terms of cause and mode of inheritance, one of the more probable explanations is de novo mutation of a dominant gene.