Wiedemann–Steiner syndrome (WSS)[2] is a rare genetic disorder that causes developmental delay, unusual facial features, short stature, and reduction in muscle tone (hypotonia).
[4] The first case was reported in 1989 by Wiedemann and colleagues which reported a Caucasian boy with pre- and postnatal growth deficiency, psychomotor delay, and a round and flat face, short nose, widely spaced eyes, long philtrum, short palpebral fissures, low-set ears, and high-arched palate.
Other findings included an alternating convergent squint, dilatation of the renal calyces, and short and thick limbs.
[5] The condition is autosomal dominant, meaning that only one abnormal copy of the gene is needed for a person to have the syndrome.
Once thought to have an incidence of 1 in 1,000,000, some research has suggested the incidence may be as high as 1 in 40,000 [5] The approximate number of WSS cases are seemingly low today but offspring of those with WSS have half the chance of having the disorder themselves.