Waardenburg syndrome

Definition

Waardenburg syndrome is a group of hereditary conditions characterized by deafness and partial albinism (pale skin, hair and eye color).

Causes, incidence, and risk factors

Waardenburg syndrome is inherited as an autosomal dominant trait; only one parent has to pass on the gene for a child to be affected. There are four types of this syndrome. (Type 3 is known as Klein-Waardenburg syndrome; Type 4 is Waardenburg-Shah syndrome.)

The multiple types of this syndrome result from mutations occurring in different genes. All types share two dominant features: hearing loss and partial albinism. The albinism is incomplete and may appear as a white forelock in an otherwise dark head of hair, very pale light-blue eyes, or two different colored eyes. Affected individuals may also have wide separation of the inner corners of the eyes, a broad nasal bridge, and other color changes of the skin.

Waardenburg syndrome affects about 1 in every 30,000 people. Almost 90% of patients have an affected parent but the symptoms in the parent can be quite different from those in the child.

Symptoms

• family history of parent with Waardenburg syndrome
  
• extremely pale blue eyes or eye colors don't match (heterochromia)
  
• white forelock of hair or early graying of the hair
  
• deafness (variable degree)
  
• possible slight decrease in intellectual functioning
  
• occasional cleft lip
  
• constipation may occur
  
• may have difficulty with completely straightening joints (contracture)
  

Signs and tests
Examination may show various abnormalities, including:

• lateral displacement of inner canthi (corners of eye)
  
• eyebrows flare in the midline
  
• broad nasal bridge
  
• deafness (may or may not be present)
  
• pale to white portions of eye including back of the eye
  
• small or under-developed bones of the face
  
• white patches of skin
  

Tests:

• audiometry (hearing evaluation)
  
• genetic testing of the PAX3 gene on chromosome 2q35
  
• genetic testing of the MITF gene (type 2 Waardenburg syndrome) on chromosome 3p13