Overexpression of YWHAE is associated with macrosomia, mild developmental delay, autism and facial dysmorphisms, and deletion of PAFAH1B1 alone leads to isolated lissencephaly (ILS).
While deletion of chromosome 17p13.3 (encompassing PAFAH1B1 and YWHAE genes) is known to result in Miller-Dieker syndrome (OMIM 247200), 17p13.3 microduplication gives rise to a condition commonly associated with developmental delay and autism spectrum disorder.
Isolated duplications of PAFAH1B1 have been associated with mild developmental delay and hypotonia, while isolated duplications of YWHAE have been associated with autism.
Duplication of YWHAE and surrounding genes increases the risk for macrosomia, mild developmental delay and pervasive developmental disorder, and results in shared facial dysmorphologies.
PAFAH1B1/LIS1 and YWHAE, which were deleted in isolated lissencephaly (PAFAH1B1/LIS1 alone) and Miller-Dieker syndrome (both genes), were found to be duplicated in patients with developmental delay.