Primary familial brain calcification

Primary familial brain calcification is a condition marked by abnormal calcium deposits in brain blood vessels, often leading to progressive movement disorders and psychiatric problems, though severity varies widely.

Overview

Primary familial brain calcification is a condition characterized by abnormal deposits of calcium (calcification) in blood vessels within the brain. These calcium deposits are visible only on medical imaging and typically occur in the basal ganglia, which are structures deep within the brain that help start and control movement of the body. Other brain regions may also be affected.

The main signs and symptoms of primary familial brain calcification are movement disorders and psychiatric or behavioral problems. These difficulties usually begin in mid-adulthood, and worsen over time. Most affected individuals have a group of movement abnormalities called parkinsonism, which include unusually slow movement (bradykinesia), muscle rigidity, and tremors. Other movement problems common in people with primary familial brain calcification include involuntary tensing of various muscles (dystonia), uncontrollable movements of the limbs (choreoathetosis), and an unsteady walking style (gait).

Psychiatric and behavioral problems occur in 20 to 30 percent of people with primary familial brain calcification. These problems can include difficulty concentrating, memory loss, changes in personality, a distorted view of reality (psychosis), and decline in intellectual function (dementia). Affected individuals may also have difficulty swallowing (dysphagia), impaired speech, headache, episodes of extreme dizziness (vertigo), seizures, or urinary problems.

The severity of primary familial brain calcification varies among affected individuals; some people have no symptoms related to the condition, whereas others have significant movement and psychiatric problems.

Frequency

Primary familial brain calcification was thought to be a rare disorder; however, because brain imaging tests are needed to see the calcium deposits, this condition is believed to be underdiagnosed. Recent research has indicated that primary familial brain calcification may occur in 2 to 6 per 1,000 people, with many affected individuals not showing signs and symptoms of the condition.

Causes

Primary familial brain calcification is caused by mutations in one of several genes. The most commonly mutated gene is called SLC20A2, and accounts for an estimated 40 percent of cases, followed by the PDGFRB gene