Björnstad syndrome
Björnstad syndrome is an autosomal recessive congenital condition involving pili torti, sensorineural deafness, and hair abnormalities. It was first characterized in 1965, in Oslo, by prof. Roar Theodor Bjørnstad after he observed an association between pili torti and hearing loss. The condition is extremely rare, with less than 50 cases documented in medical literature worldwide.
| Björnstad syndrome | |
|---|---|
| Other names | BJS, Deafness and pili torti (Bjornstad type), Pili torti and nerve deafness, Pili-torti deafness syndrome, Pili torti-sensorineural hearing loss, PTD |
| Symptoms | Pili torti, hearing loss, alopecia, mental retardation |
| Usual onset | Infancy or early childhood |
| Causes | Mutation of BCS1L |
| Frequency | Extremely rare - less than 50 documented cases |
Björnstad syndrome is caused by mutations of the BCS1L gene. The protein product of this gene is BCS1L, which plays an important role in oxidative phosphorylation. Mutated BCS1L increases production of reactive oxygen species, which may be the molecular cause of pili torti and hearing loss, both of which are associated with Björnstad syndrome. Pili torti is recognized in early childhood and is characterized by twisted hair shafts and brittle hair. The hearing loss usually becomes evident very early in life as well, often in the first year.