Waardenburg syndrome

The Waardenburg syndrome consists of a group of genetic disorders that can lead to hearing loss and changes in pigmentation of hair, eyes and skin.

This condition was first described by Dutch ophthalmologist Petrus Johannes Waardenburg, in 1951, as an autosomal dominant condition with variable penetrance and expressivity of his characters.

The incidence of this syndrome varies between 1:30000 and 1:42000, accounting for approximately 3% of cases of hearing impairment in children.

There are four distinct types of Waardenburg syndrome, which are:

• Type I: related to the mutation in PAX3. Patients have this type epicanthus (skin fold extending from the base of the nose to the end of the medial brow, called dystopia canthorum), more distance than normal between the internal medial corner of the eye, iris isocromia staining bright blue or heterochromia of the iris (color difference between both iris), white streaks in her hair, eyebrows and confluence of change in skin pigmentation.

• Type II: linked to mutations in the MITF gene. This type is very similar to Type I, except that in this type there is the absence of dystopia canthorum.

• Type III: This type is also known as Klein-Waardenburg syndrome and it is a rare syndrome that, in addition to presenting the demonstrations oculoauditivas and pigmentation found in type I, also has microcephaly, malformations of the upper and mental disability. Mutation of this type find yourself on the long arm of chromosome 2.

• Type IV: This type is also known as Waardenburg-Shah syndrome and is similar to the type II presenting Hirschsprung's disease, autosomal recessive, can receive the name of congenital megacolon. The condition usually appears soon after birth, is more common in males, causing severe constipation, bloating and, in some cases, vomiting and, if severe growth retardation. This type associated with mutations in the gene EDNRB.

Diagnosis and Treatment

The diagnosis is made based on the clinical picture presented by the patient. Some tests may assist in closing the diagnosis, such as audiometry, colon biopsy and genetic testing.

To date there is no treatment and no cure for Waardenburg syndrome. The typical symptom that is deafness, it is treated as any other irreversible hearing loss. Other problems, such as neurological, structural and Hirschsprung's disease are treated symptomatically.