Wiedemann-Steiner Syndrome Testing (KMT2A (MLL))

Wiedemann-Steiner syndrome [OMIM#605130] is a rare disorder characterized by excessive growth of terminal hair around the elbows (hypertrichosis cubiti), short stature, intellectual disability and characteristic facial features. Facial features include long eyelashes, think or arched eyebrows, downslanting and vertically narrow palpebral fissures, broad nasal bridge and wide nasal tip.

Jones et al. (2012) identified mutations in KMT2A (MLL) [OMIM#159555] in five out of six patients with clinical features consistent with Wiedemann-Steiner syndrome. All mutations were predicted to result in protein truncation. KMT2A encodes for a histone methyltransferase that regulates chromatin-mediated transcription.