Abstract

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

Symptoms/signs

The symptoms and/or signs of branchio-oto-renal syndrome are consistent with underdeveloped (hypoplastic) or absent kidneys with resultant renal insufficiency or renal failure. Ear anomalies include extra openings in front of the ears, 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. People with BOR may also have cysts or fistulae along the sides of their neck.

Cause

The cause of branchio-oto-renal syndrome are mutations in genes, EYA1, SIX1, and SIX5 (approximately 40 percent of those born with this condition have a mutation in the EYA1 gene).

Mechanism

The genetics of branchio-oto-renal syndrome indicate it 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. This gene is involved in many facets of embryonic development and is important in the normal formation of many organs and tissues, including the ears, and kidneys before birth.

Diagnosis

The diagnosis of this syndrome can be done via the test "Branchiootorenal syndrome via the SIX5 Gene" whose purpose is mutation confirmation and risk assessment (screening).

Treatment

The treatment of branchio-oto-renal syndrome is done per each affected area (or organ). For example, a person with hearing problems should have appropriate supports and prompt attention for any inflammation of the ear.

A specialist should observe any kidney problems. Surgical repair may be needed depending on the degree of a defect or problem, whether a transplant or dialysis is needed.

Treatment | Epidemiology

The epidemiology of branchio-oto-renal syndrome has it with a prevalence of 1/40,000 in Western countries.A 2014 review found 250 such cases in the country of Japan