The syndrome of Waardenburg: signs, causes, type of inheritance

One of the groups of diseases are congenital pathologies. In most cases, it is impossible to prevent them. About such conditions are recognized after the birth of the baby. Genetic diseases are characterized by various manifestations. In most cases, these are internal organs and external anomalies. One of the congenital pathologies is the syndrome of Waardenburg. It has characteristic features that distinguish it from other genetic defects. These include: hearing impairment, different eye color, specific appearance of patients. To diagnose this ailment requires a survey of several specialists.

What is the syndrome of Waardenburg?

This disease does not apply to rare genetic defects. On average, the incidence of pathology is 1 to 4,000 newborns. The syndrome of Waardenburg can be suspected already at an early age, because its main manifestations are the striking unusual appearance of the baby and hearing loss. The disease was described in the middle of the twentieth century. Opened this genetic pathology ophthalmologist from France in Vaardenburg. He studied a group of children who had such features as the Greek profile, bright eye color (in some cases, different) and deafness. In addition, the syndrome has many other manifestations, the combination of which may differ.

The disease is diagnosed in both girls and boys. The incidence of the disease is not related to gender and nationality. The risk of developing this pathology rises sharply if there is a genetic anomaly in one of the family members. Currently, there are several varieties of the syndrome of Waardenburg. The classification is based on genetic changes.

Causes of pathology development

One of the relatively recently discovered congenital diseases is the syndrome of Waardenburg. The type of inheritance of this pathological condition is autosomal dominant. This implies a high risk of transferring defective genes from parents to children. The probability of inheriting the disease is 50%. The cause of the development of the disease are mutations in some genes. One of them is responsible for the formation of melanocytes - pigment cells. Mutations of this gene cause unusual color of eyes and heterochromia (different coloring of irises).

Sometimes the disease is not associated with burdened heredity. In such cases, one can not say for what reason genetic alterations have occurred. It is known that they occur during the period of intrauterine development. Risk factors include infectious pathologies that occur during pregnancy. Also, the cause may be stressful effects, drug intoxication, bad habits, etc.

Varieties of pathological condition

There are 4 types of the syndrome of Waardenburg. They are classified according to the type of inheritance and the nature of genetic disorders. Most often, the first type of pathology occurs. It is characterized by a mutation of the gene MITF and PAX3, located in the second chromosome. The type of inheritance is autosomal dominant. The PAX3 gene is responsible for the production of the transcription factor, which in turn controls the migration of neural crest cells.

The second type of the syndrome of Waardenburg is observed in 20-25% of cases. Pathological genes are located in chromosome 3 and 8. The first - is involved in the formation of pigment cells. The second is responsible for the coding of factors that activate the transcription of proteins.

At the third type of disease there is a violation of the PAX3 gene. This type of pathology is distinguished by the severity of the flow. Unlike the first type, the mutating gene is not in the hetero-, but in the homozygous state. Sometimes there are nonsense mutations.

The fourth type of disease is characterized by autosomal recessive inheritance. The risk of transmission of pathology is 25%. The defective gene is localized in chromosome 13. It is involved in the formation of the B-endothelin protein.

The syndrome of Waardenburg: symptoms of the disease

There are large and small criteria of pathology. The first are found in most cases. These include:

1. Heterochromy. People with different eyes color make up about 1% of the total population of the Earth. Heterochromia is not always associated with a pathological syndrome.
2. Offset of the inner eye angle. This phenomenon is called "television".
3. Bright blue color of the iris.
4. Having a patch of gray hair.
5. Broad bridge of nose.
6. Pronounced hearing impairment, in some cases - deafness.
7. Small proportions of the middle part of the facial skull.
8. Combination of these symptoms with Hirschsprung's disease. This pathology is characterized by a violation of the innervation of the intestinal tract.

Small symptoms may include various symptoms. Among them: finger contractures, spinal column splitting, syndactyly, skin changes (the presence of a large number of moles, leukodermia). Often there is hypoplasia of the wings of the nose and a decrease in the superciliary arches. This face configuration is referred to as the "Greek profile". Some patients have such defects as "wolf mouth" or "hare lip".

Diagnosis of congenital anomaly

People with different eye colors are rare, but this symptom does not always indicate a genetic pathology. If such a symptom is combined with the deafness and characteristic features of the appearance, then the presence of the syndrome of Waardenburg is likely. To confirm the diagnosis, specialist consultations are required. Obligatory examination otolaryngologist, ophthalmologist, dermatologist. It is important to find out the hereditary anamnesis. Genetic examination is performed to confirm the diagnosis. After it, it is determined whether there is a syndrome of Waardenburg. The level of intelligence in patients is normal. This differs this disease from many other hereditary pathologies.

Treatment of the syndrome of Waardenburg

As with other chromosomal diseases, there is no etiotropic treatment for the syndrome of Waardenburg. The actions of doctors are aimed at eliminating the symptoms of pathology. Implantation of the cochlear apparatus is performed to prevent deafness. If the pathology is combined with Hirschsprung's disease, surgery on the intestine is required. In some cases, physiotherapy is prescribed. Sometimes plastic surgery on the face.

Prevention of genetic syndrome

The likelihood that the syndrome of Waardenburg will develop in a child with a disease of one of the parents is very high. Therefore, during pregnancy, the genetic examination of the fetus is carried out. It is necessary in case of burdened heredity.

If such a disease in relatives was not observed, it is impossible to prevent the development of pathology. To prevent genetic disorders, it is recommended to avoid stresses and other factors that have a teratogenic effect. The prognosis for life in this pathology is favorable.