Waardenburg syndrome

Yes. People can have Waardenburg syndrome (WS) without having some type of heterochromia iridis. In general, heterochromia iridis is less common in affected people than the hair and skin features of WS.^[1]

In WS type 1 for example, heterochromia iridis is present in 15%-31% of affected people, and hypoplastic blue irides is present in 15%-18% of affected people.^[2] Ocular features are more common in WS type 2 than in type 1.^[1]

The white forelock may be present at birth, or it may appear later (typically in the teen years). It can also become normally pigmented over time. Red and black forelocks have also been described. The majority of people with Waardenburg syndrome type 1 have either a white forelock, or early graying of scalp hair (before age 30).^[2]

Type 4 Waardenburg syndrome (also called Waardenburg-Shah syndrome) is characterized by symptoms of Hirschsprung's disease in addition to the classic features of hearing loss and pigmentation abnormalities.^[3][2] Hirschsprung's disease is a digestive (gastrointestinal) disorder in which nerves are missing from part of the bowel, impairing the ability to move material through the bowel. This causes a blockage, which in turn causes contents of the intestine to build up behind the blockage. As a result, the bowel and abdomen swell.^[4] We are not aware of other gastrointestinal problems typically associated with Waardenburg syndrome.

A diagnosis of Waardenburg syndrome (WS) is made based on the presence of signs and symptoms. In 1992, the Waardenburg Consortium proposed diagnostic criteria, which includes both major and minor criteria. A diagnosis of WS type 1 (the most common type) needs 2 major, or 1 major and 2 minor of the following criteria:^[2][5]

Major criteria:

• Congenital sensorineural hearing loss (present from birth)
• Iris pigmentary (coloration) abnormality, such as heterochromia iridis (complete, partial, or segmental); pale blue eyes (isohypochromia iridis); or pigmentary abnormalities of the fundus (part of the eye opposite the pupil)
• Abnormalities of hair pigmentation, such as white forelock (lock of hair above the forehead), or loss of hair color
• Dystopia canthorum – lateral displacement of inner angles (canthi) of the eyes (in WS types 1 and 3 only)
• Having a 1st degree relative with Waardenburg syndrome

Minor criteria:

• Leukoderma (white patches of skin) present from birth
• Synophrys (connected eyebrows, or "unibrow") or medial eyebrow flare
• Broad or high nasal bridge (uppermost part of the nose)
• Hypoplasia (incomplete development) of the nostrils
• Premature gray hair (under age 30)

WS type 2 has features similar to type 1, but the inner canthi of the eyes are normal (no dystopia canthorum present).

WS type 3 also has similar features to WS type 1, but is additionally characterized by musculoskeletal abnormalities such as muscle hypoplasia; flexion contractures (inability to straighten joints); or syndactyly (webbed or fused fingers or toes).

WS type 4 has similar features to WS type 2, but with Hirschsprung disease (a condition resulting from missing nerve cells in the muscles of part or all of the large intestine).^[5]