Branchio-oto-renal syndrome

Branchio-oto-renal syndrome (BOR), also known as branciootorenal syndrome or BOR syndrome, is an autosomal dominant genetic disorder involving the kidneys, ears, and neck. It has also been described as Melnick-Fraser syndrome after Frank Clarke Fraser and Michael Melnick.

Presentation
Individiduals with BOR may have underdeveloped (hypoplastic) or absent kidneys with resultant renal insufficiency or renal failure.

Ear anomalies include extra openings in front of the ears (preauricular pits), extra pieces of skin in front of the ears (preauricular tags), or further malformation or absence of the outer ear (pinna). Malformation or absence of the middle ear is also possible. Individuals can have mild to profound hearing loss, which can either be sensorineural, conductive, or mixed. People with BOR may also have cysts or fistulae along the sides of their neck corresponding to the location of the embryologic branchial clefts.

Genetics


BOR is inherited in an autosomal dominant manner, and results from a mutation in the EYA1 gene. Autosomal dominant inheritance indicates that the defective gene responsible for a disorder is located on an autosome, and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.