Waardenburg Syndrome
Created | Updated Jan 31, 2002
Waardenburg Syndrome (WS) is not as severe as other genetic disorders, as its effects are physical as opposed to mental, but can still affect the daily life of the afflicted. It was named after the Dutch eye doctor Petrus Johannes Waardenburg who noticed that his patients with differently colored eyes (heterochromia) also suffered from hearing loss. He then went on to study over a thousand patients with a history of hearing loss in their family and found several physical traits that were shared.
Types of the Disorder
There are at least four types of WS, the most common named Type 1 and Type 2. The different types are defined by the distinct physical traits of those beset with the syndrome. Patients with Type 1 have an unusually wide space between the corners of their eyes. Twenty percent of individuals with Type 1 experience hearing loss. Those with normal eye spacing but many other WS traits have Type 2. About half of these patients have hearing impairments.
Some Symptoms
The symptoms of WS include a blaze of white or gray in otherwise normally colored hair, abnormally spaced eyes, one brown and one blue eye or brilliantly blue eyes. Connected eyebrows, a broad nose and a low frontal hairline are also common phenotypes of WS. An afflicted individual may have all of these symptoms or only a few.
Since the effects of this disorder are mostly physical and the only serious symptom is hearing loss, anyone affected lives a substantially normal life, just like any deaf person. Of course, some teasing may occur during childhood, but that is fairly normal and nearly everyone experiences that sort of persecution.
The Genetics and Effects of WS
This autosomal dominant disorder is caused by four genes: PAX3, MITF, EDNRB, and EDN3. These are found on the second and third chromosomes. Two genes, PAX3 and MITF, affect the development of the ear and little is known about the other two. Research continues to be done on these genes to further the understanding of genetics and this disorder.
WS affects the development of the ears and face throughout the maturation of a patient, and is therefore not usually diagnosed until later in life. Heterochromatic patients can be diagnosed at an earlier age, however.
Because the allele1 is dominant, there is a 50/50 chance of offspring inheriting the disorder from a parent who is heterozygous for the disorder. If a parent is homozygous dominant, 100% of their children will have the syndrome as the dominant gene will override any other genetic material received for WS.
Treating WS
There is no treatment for WS, and since it is a developmental disorder and does not produce symptoms until adolescence, gene therapy has not been used to treat this syndrome. Genetic counseling is available, and affected parents can decide whether to have children. Not everything is known or understood about this disease, and the future may hold an answer for those looking for a cure.
WS is a fairly benign disorder, with only a fraction of those afflicted suffering from hearing loss. Most just have odd physical characteristics. Due to the mild nature of this disorder, a cure is not what the research is seeking, but a greater understanding of the very structure that controls and directs the development of all life on Earth.
1A member of a pair of genes for a specific trait on a specific chromosome.
