Klein-waardenburg syndrome E70.32

Rare, autosomal-dominantly inherited, clinical variant (WS III) of 4 genetically different main forms of Waardenburg syndrome with the clinical constellation of:

• White forelock
• sensoneural hearing loss
• Blepharophimosis
• Heterochromia (possibly radiant blue iris)

S.a.u. Waardenburg Syndrome.

Prevalence: 1-2/100.000

Autosomal-dominant ebbs with variable penetrance and expressiveness. Mutations in the PAX3 gene (2q35-q37). The PAX3 gene is an important regulator gene for the differentiation of neural crest cells.

• Integument: Hyper- or hypopigmentation in the hair and face area. Hair anomalies in the form of deep drawn forehead hairline with relatively thicker hair diameter as well as persistent lanugo hair (more rarely). Furthermore, Piebaldism with white pigment-less hair strands on the forehead hairline in the area of the midline as well as medially localized white parts of the eyebrows is possible.
• Extracutaneous manifestations: Congenital inner ear deafness or profound inner ear deafness with deaf-mute. Partial or total iris heterochromia or bilateral blue iris. Dysplasia of the interocular area with pseudohypertelorism due to lateral displacement of the inner eye corners and tear points (dystopia canthi) and shortening of the eyelid fissure length (blepharophimosis). More rarely, there is also genuine hypertelorism and hyperplasia of the medial part of the eyebrows as well as hyperplasia of the bony part of the nose with broad, high nasal root. Short stature; brachycephaly with shortening of the front part of the base of the skull; jaw and tooth position anomalies. Eye involvement with hyperopia and astigmatism (more rarely) as well as further pigment anomalies at the ocular fundus.

1. Böhm M (2015) Differential diagnosis of hypomelanosis. dermatologist 66: 945-958
2. Hoth CF, Milunski A, Lipsky N et al (1993) Mutations in the paired domain of the human PAX3 gene cause Klein-Waardenburg syndrome (WS-III) as well as Waardenburg syndrome type I (WS-I). At J Hum Genet 52: 455-462
3. Klein D (1947) Albinisme partiel (leucisme) accompagné de surdi-mutité, d'ostéo-myodysplasia, de raideurs articulaires congénitales multiples et d'autres malformations congénitales. Arch Klaus Foundation 22: 336-342
4. Waardenburg PJ (1951) A new syndrome combining development anomalies of the eyelids, eyebrows and nose root with pigmentary defects of the iris and head and with congenital deafness. On J Hum Genet 3: 195-253
5. Wollnik B et al (2003) Homozygous and heterozygous inheritance of PAX3 mutations causes different types of Waardenburg syndrome. At J Med Genet 122A: 42-45