Waardenburg syndrome or Waardenburg-Klein syndrome is a rare genetic disorder most often characterized by varying degrees of deafness, minor defects in structures arising from the neural crest, and pigmentation anomalies.
Symptoms vary from one type of the syndrome to another and from one patient to another, but they include: Very pale or brilliantly blue eyes, eyes of two different colors (complete heterochromia), or eyes with one iris having two different colours (sectoral heterochromia); A forelock of white hair (poliosis), or premature graying of the hair; Wide-set eyes (hypertelorism) due to a prominent, broad nasal root (dystopia canthorum—particularly associated with type I); Moderate to profound hearing impairment (higher frequency associated with type II); and A low hairline and eyebrows that touch in the middle. Patches of white pigmentation on the skin have been observed in some people. Sometimes, abnormalities of the arms, associated with type III, have been observed.
This condition is usually inherited in an autosomal dominant pattern, which means one copy of the altered gene is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. A small percentage of cases result from new mutations in the gene; these cases occur in people with no history of the disorder in their family.