Pendred syndrome can be caused by changes, or mutations, to a gene known as SLC26A4 (also referred to as the PDS gene) on chromosome 7. Because it is a recessive trait, a child needs to inherit two mutated SLC26A4 genes—one from each parent—to have Pendred syndrome. The child’s parents do not need to have Pendred syndrome to be a carrier of a mutation in the SLC26A4 gene.

Couples who are concerned that they might be able to pass Pendred syndrome on to their children may seek genetic testing. A possible sign that a person may be a carrier of a mutated SLC26A4 gene is a family history of early hearing loss. Another sign is a family member who has both a goiter and hearing loss. A mutation in the SLC26A4 gene can be determined by genetic testing that uses a blood sample.

The decision to have a genetic test is complex. Most people receive assistance from a genetic counselor trained to help them weigh the medical, emotional, and ethical considerations. A genetic counselor is a health professional who provides information and support to individuals and families who have a genetic disease or who are at risk for such a disease.