Waardenburg Syndrome

An auditory pigmentary syndrome characterized by hypopigmentation of the skin, iris, hair and stria vascularis of the cochlea. Most patients present with two different colored eyes, white forelock and eyelashes, and premature graying of the hair. Moderate acrocephaly, lack of osseous fusion of the short tubular bones, oligodactyly of the feet, short stature, pericardial cysts, rectal prolapse, and deformed ears are reported. Other features include hypoplastic maxilla, asymmetry of hands, deformity of the first phalanx of the head, absence of the first digit of the foot, and bifid distal phalanges of the second and third toes.

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Petrus Johannes Waardenburg Syndrome (Dutch ophthalmologist, 1886-1979); WS I.

All forms of WS together, estimates are that about 1:40,000 individuals of the general population are affected by this disorder, which may be responsible for up to 3% of patients with congenital deafness. In Kenya, the estimated frequency is reported at 1:20,000 persons. It is also reported at 1:212,000 individuals in the general population of the Netherlands.

(see also Clinical Aspects) Autosomal dominant inheritance characterizes Waardenburg Syndrome Type 1 (WS 1), which has been mapped to 2q35. If dystopia canthorum (lateral displacement of the inner canthi of the eyes) is absent, the syndrome is called WS Type 2. WS 3 is a severe form of this disorder in which both, heterozygosity and homozygosity of mutations in the PAX3 gene (paired box gene 3) have been reported.

Almost all cases are at least due in part to mutations of the PAX3 gene (paired box gene 3), which is involved in the formation of the caudal neural crest derivatives and the migration of myoblasts into the extremities. Children with this syndrome have a normal life expectancy.

Two major or one major plus two minor features must be present for the diagnosis. Major features: congenital sensory hearing loss and pigmentary disturbance of the iris with different-colored eyes or segmental heterochromia; hair hypopigmentation; affected first-degree relative. Minor features: congenital leukoderma, medial eyebrow flare, high nasal root, nasal alae hypoplasia, premature graying of scalp.

Four different types of Waardenburg Syndrome have been defined:

Waardenburg Syndrome Type 1 (WS 1): It was in 1947, when the Dutch ophthalmologist and geneticist Petrus Johannes Waardenburg first presented a patient with sensorineural hearing loss, dystopia canthorum (lateral displacement of the inner canthi of the eyes), hypertrichosis of the medial aspect of the eyebrows, broad nasal bridge, and pigment anomalies of skin (albinism), iris (heterochromia iridis) retina, and hair (white forelock or poliosis) to the Swiss Society of Genetics. After he found several more patients with ...