CYP7B1-Related Oxysterol Accumulation Disorder
Autosomal recessive
Caused by loss-of-function changes in both copies of CYP7B1, which encodes oxysterol 7-alpha-hydroxylase, an enzyme in bile acid production. Its loss is linked to spastic paraplegia type 5 and, in some people, liver disease.
Signs and symptoms
People can have hereditary spastic paraplegia type 5, with progressive stiffness and weakness of the legs beginning anywhere from childhood to adulthood, sometimes with reduced vibration sense and bladder control problems. Some also have changes in the white matter of the brain on MRI. In some families there is also liver disease, such as chronic autoimmune hepatitis or cirrhosis.
What a diagnosis changes
Spastic paraplegia is managed with physiotherapy, antispasticity medicines and mobility aids. People with liver disease are treated by specialist hepatology teams. Both parents of an affected child are usually carriers, so each further child has a 1 in 4 chance of being affected; genetic counselling and carrier testing of relatives are available.
Genes analysed
Includes 2 related subtypes ↓Hide subtypes ↑
- congenital bile acid synthesis defect 3
- hereditary spastic paraplegia 5A
