SNP Shot: Genomic Insights

Friedreich ataxia is an inherited disease that damages the nervous system, leading to difficulties with movement. A key symptom is ataxia, or poor muscle coordination, which gets progressively worse. Other symptoms include weakening and loss of feeling in the limbs, stiff muscles (spasticity), and problems with speech, hearing, and eyesight. Many people with Friedreich ataxia also develop hypertrophic cardiomyopathy, a dangerous heart condition where the heart muscle becomes enlarged and weakened. Diabetes and scoliosis (an abnormal spinal curve) can also occur.

The first signs of Friedreich ataxia usually appear between the ages of 5 and 15. The initial symptoms are often poor coordination and balance. Most affected individuals will need to use a wheelchair around a decade after the symptoms start.

Approximately one-quarter of people with Friedreich ataxia have an unusual form of the disease where symptoms start after age 25. If the condition begins between ages 26 and 39, it's called late-onset Friedreich ataxia (LOFA). If symptoms start after age 40, it's called very late-onset Friedreich ataxia (VLOFA). LOFA and VLOFA typically progress more slowly compared to the more common form of Friedreich ataxia.

Inheritance:

Friedreich ataxia follows an autosomal recessive inheritance pattern. This means that a person must inherit two mutated copies of the responsible gene, one from each parent, to develop the condition. While each parent carries one copy of the mutated gene, they generally don't exhibit any symptoms of the disease themselves.