Published online Jun 20, 2020. doi: 10.5496/wjmg.v9.i1.1
Peer-review started: March 14, 2020
First decision: April 12, 2020
Revised: April 19, 2020
Accepted: May 14, 2020
Article in press: May 14, 2020
Published online: June 20, 2020
Wiedemann-Steiner syndrome (OMIM #605130) is a rare congenital malformation syndrome characterized by hypertrichosis cubiti associated with short stature; consistent facial features, including long eyelashes, thick or arched eyebrows with a lateral flare, wide nasal bridge, and downslanting and vertically narrow palpebral fissures; mild to moderate intellectual disability; behavioral difficulties; and hypertrichosis on the back. It is caused by heterozygous pathogenic variants in KMT2A. This gene has an established role in histone methylation, which explains the overlap of Wiedemann-Steiner syndrome with other chromatinopathies, a heterogeneous group of syndromic conditions that share a common trigger: The disruption of one of the genes involved in chromatin modification, leading to dysfunction of the epigenetic machinery.
Core tip: Chromatinopathies are a highly heterogeneous group of syndromic conditions in which the underlying genetic anomaly consists of disruption of one of the components of the epigenetic machinery. Within this group, which contains more than 40 diseases, including Kabuki, Sotos, Kleefstra, Koolen-De-Vries/KANSL1 haploinsufficiency, Rubinstein-Taybi, KAT6B-related syndromes, Smith-Magenis, Rett, Townes-Brock, Bohring-Opitz, ATRX, CHARGE, and Floating-Harbor syndromes, an emerging member is represented by Wiedemann-Steiner syndrome, which has very interesting features.