Bjornstad Syndrome is a rare genetic condition that primarily affects an individual’s hearing and hair. This inherited disorder can manifest with varying degrees of severity. Understanding its characteristics is key to identifying its presence and providing appropriate support.
Defining Bjornstad Syndrome
Bjornstad Syndrome is a rare condition characterized by sensorineural hearing loss and a distinctive hair abnormality known as pili torti. This inherited disorder was first described in 1965, linking these two symptoms. Fewer than 50 cases have been documented in medical literature worldwide. Symptoms typically begin to appear before the age of two.
Understanding the Symptoms
Sensorineural hearing loss, which means the inner ear or auditory nerve is affected, often presents congenitally or in early childhood. The severity of this hearing loss can vary significantly among individuals, ranging from an inability to hear certain frequencies to complete deafness in both ears.
Pili torti, meaning “twisted hair,” is a hair shaft abnormality. Under a microscope, the hair strands appear flattened and twisted 180 degrees at irregular intervals. This structural weakness makes the hair dry, fragile, coarse, and prone to breakage, often leading to sparse hair or patchy hair loss. While it typically affects scalp hair, it can also involve eyebrows and eyelashes in some cases.
The Genetic Cause
Bjornstad Syndrome is caused by specific alterations in the BCS1L gene. This gene is located on chromosome 2 (specifically, position 2q35) and plays a role in mitochondrial function. The protein produced by the BCS1L gene is involved in the assembly of Complex III, a part of the oxidative phosphorylation process within cells. Mutations in this gene can impair the formation of Complex III, affecting cellular energy production and increasing reactive oxygen species.
The inheritance pattern for Bjornstad Syndrome is autosomal recessive. This means that an individual must inherit two copies of the altered BCS1L gene, one from each parent, to develop the condition. Parents who carry one copy of the altered gene are typically unaffected themselves, as they also have a functional copy. The condition can affect both males and females equally.
Diagnosis and Management
Diagnosing Bjornstad Syndrome begins with observing characteristic symptoms. Clinical examination will note the presence of pili torti, which may be apparent at birth or within the first months of life. Audiometric testing is then performed to confirm sensorineural deafness. A definitive diagnosis is often achieved through a microscopic examination of hair shafts, which reveals the distinctive twisted appearance.
Genetic testing for mutations in the BCS1L gene provides confirmation of Bjornstad Syndrome. Since there is no specific cure, management focuses on alleviating symptoms and providing supportive care. For hearing loss, interventions like hearing aids or cochlear implants can significantly improve auditory function. General hair care advice, such as gentle handling and avoiding harsh treatments, can help manage the brittle hair. Early diagnosis and intervention are beneficial for optimizing outcomes, particularly for hearing development and communication skills.