Wiedemann-Steiner syndrome

Wiedemann-Steiner Syndrome (WDSTS) is a rare autosomal dominant disorder characterized by hairy elbows, dysmorphic facial appearances (hypertelorism, thick eyebrows, downslanted and vertically narrow palpebral fissures), pre- and post-natal growth deficiency, and psychomotor delay. Sharing clinical features with Cornelia de Lange syndrome, WDSTS is another heterogeneous disease. WDSTS is caused by heterozygous mutations in KMT2A, also known as MLL. KMT2A encodes a histone methyltransferase that plays an important role in early development and hematopoiesis. Recently, an autosomal-recessive disorder with Cornelia de Lange syndrome-like features has been reported and termed Alazami-Yuan syndrome. It is caused by homozygous mutations in TAF6, which encodes a core transcriptional regulatory pathway component.