Cerebrotendinous Xanthomatosis (CTX)

Cerebral Cholesterinosis; Sterol-27-hydroxylase deficiency

Inheritance:

Autosomal recessive

Inheritance from both parents will result in the disease

Age range at onset:

Neonatal or infant

Specialists you may see:

Symptoms

A common first sign of CTX is neonatal cholestastatic (reduction or stoppage of bile flow) jaundice , shown as yellowing of the skin and whites of the eyes, itchy skin, dark urine and light-coloured, foul-smelling stools. Chronic diarrhoea and liver dysfunction may also occur. Children with CTX often suffer from cataracts. Xanthomas (yellowish, cholesterol-rich deposits showing abnormal storage of fats and occurring anywhere on the body,) are common on the elbow, hand, patella, neck and Achilles tendon.

While some intellectual impairment may be noticed in childhood, this is more common from puberty onwards. Dementia, psychiatric disturbances and nerve damage progress with age, with dementia often happening in a person’s twenties alongside behavioural changes. These changes may include hallucinations, aggression, depression and suicidal tendencies.

Life expectancy without treatment is around 50-60 years, with some deaths reported in infancy.

Cause

CTX is caused by mutations in the CYP27 gene resulting in deficient activity of chemical sterol-27-hydroxylas which is important in initiating the Bile Acid Synthesis (BAS) pathway. This means that bile acid synthesis is disrupted, creating a build up of cholesterol and cholestenol causing the degenerative problems described.

News, research and treatment

Treatment of CTX is possible through CDCA (chenodeoxycholic acid) replacement therapy, which can halt and even reverse symptoms. Cholic acid treatment is another alternative treatment.

Patients in the UK should refer to the NHS Clinical Commissioning Policy: Cholic acid and chenodeoxycholic acid for treating inborn errors of bile acid synthesis (all ages)