Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy
Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is an inherited condition that causes stroke and other neurological impairments.
Overview
CARASIL is a rare inherited disorder that typically manifests in an individual's twenties or thirties. The condition is characterized by progressive neurological decline, including stroke, dementia, and movement disorders. Most affected individuals die within a decade of the onset of symptoms.
Symptoms
The signs and symptoms of CARASIL worsen slowly over time and include:
- Muscle stiffness (spasticity) in the legs and walking difficulties.
- Stroke or stroke-like episodes (occurring in about half of affected individuals before age 40).
- Mood and personality changes.
- Decline in thinking ability (dementia) and memory loss.
- Premature hair loss (alopecia), often beginning in adolescence.
- Attacks of low back pain caused by the degeneration of discs between the vertebrae.
Causes
CARASIL is caused by mutations in the HTRA1 gene. This gene provides instructions for making an enzyme that regulates signaling by proteins in the transforming growth factor-beta (TGF-β) family. In affected individuals, these mutations prevent effective regulation of TGF-β signaling, which is believed to alter the structure of small blood vessels in the brain (arteriopathy). These vascular abnormalities increase the risk of stroke and lead to the death of nerve cells (neurons).
Inheritance
This condition is inherited in an autosomal recessive pattern. This means that both copies of the gene in each cell must have mutations for the condition to occur. Parents of an affected individual typically carry one copy of the mutated gene but do not show signs or symptoms of the disorder.
Other Names
- CARASIL
- Familial young-adult-onset arteriosclerotic leukoencephalopathy with alopecia and lumbago without arterial hypertension
- Maeda syndrome
- Nemoto disease