Pendred's Syndrome

Definition

Pendred's syndrome is characterised by deafness associated with a goitre due to an enzyme defect in the ear and thyroid gland. Usually the child is not hypothyroid.

Incidence

It is thought to affect 75 in one million people, and to account for 10% of all congenital deafness.

Inheritance

The gene defect has been localised to chromosome 7. The pattern of inheritance is autosomal recessive, meaning if both parents are carriers of the disease there is a 25% chance of having an affected child.

Risk to Further Offspring

The risk of having a further affected child is 25% and the risk of having a child who is a carrier is 50%.

Symptoms

The child may present with deafness, which is usually severe, from birth. The goitre may not develop until puberty, delaying the diagnosis of the disease. If hypothyroidism is present from birth the child may be floppy and cold with dry skin. They may also be constipated.

Signs

If hypothyroidism is present at birth they may have a large birth weight. They may also have an umbilical hernia and a large protruding tongue.

Complications

If the hypothyroidism is not detected early it will cause retardation of growth and mental development.

Treatment

All newborn babies in this country are screened for hypothyroidism. If this is detected it is treated early with thyroid replacement hormones.

Outcome

If replacement is adequate it should prevent the mental and growth retardation. Deafness will not respond to hormone replacement.