CARASIL

A rare genetic disorder affecting the brain and blood vessels

CARASIL (Cerebral Autosomal Recessive Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) is a rare genetic disorder characterized by a combination of neurological and dermatological symptoms. It is an autosomal recessive condition, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disease.

Genetics

Diagram showing autosomal recessive inheritance pattern

CARASIL is caused by mutations in the HTRA1 gene, which is located on chromosome 10. The HTRA1 gene encodes a serine protease enzyme that is involved in the degradation of proteins in the extracellular matrix. Mutations in this gene lead to the accumulation of abnormal proteins, which affects the integrity of small blood vessels in the brain.

Clinical Features

The clinical presentation of CARASIL includes a range of symptoms that typically begin in early adulthood. The most prominent features are:

Neurological Symptoms

• Subcortical Infarcts: Patients experience multiple small strokes, leading to progressive cognitive decline and dementia.
• Leukoencephalopathy: This refers to changes in the white matter of the brain, visible on magnetic resonance imaging (MRI) scans, which contribute to neurological deficits.
• Gait Disturbance: Difficulty in walking due to spasticity and weakness is common.

Dermatological Symptoms

• Alopecia: Early-onset hair loss, particularly affecting the scalp, is a characteristic feature.
• Spondylosis: Degenerative changes in the spine, leading to back pain and stiffness.

Diagnosis

The diagnosis of CARASIL is based on clinical evaluation, family history, and genetic testing. MRI scans are used to identify characteristic changes in the brain, while genetic testing confirms mutations in the HTRA1 gene.

Management

There is currently no cure for CARASIL, and treatment is primarily supportive. Management focuses on alleviating symptoms and preventing complications. This may include:

• Physical Therapy: To improve mobility and manage spasticity.
• Cognitive Therapy: To support cognitive function and manage dementia.
• Pain Management: For symptoms related to spondylosis.

Prognosis

The progression of CARASIL is variable, but it generally leads to significant disability over time. The disease course is progressive, with worsening neurological and physical symptoms.

Related pages

• Genetic disorder
• Leukoencephalopathy
• Dementia
• Stroke