Friedreich's ataxiais an inherited disease that causes progressive damage to the nervous system, resulting in symptoms ranging from gait disturbance to speech problems; it can also lead to heart disease and diabetes.The ataxia of Friedreich's ataxia results from the degeneration of nerve tissue in the spinal cord, in particular sensory neurons essential (through connections with the cerebellum) for directing muscle movement of the arms and legs. The spinal cord becomes thinner and nerve cells lose some of their myelin sheath (the insulating covering on some nerve cells that helps conduct nerve impulses). Friedreich's ataxia is an autosomal recessive congenital ataxia and is caused by a mutation in gene FXN (formerly known as X25) that codes for frataxin, located on chromosome 9. This protein is essential for proper functioning of mitochondria .
Symptoms typically begin sometime between the ages of 5 to 15 years, but in Late Onset FA may occur in the 20s or 30s. Symptoms include any combination, but not necessarily all, of the following:
Muscle weakness in the arms and legs
Loss of coordination
Vision impairment
Hearing impairment
Slurred speech
Curvature of the spine (scoliosis)
High plantar arches (pes cavus deformity of the foot)
Diabetes (about 20% of people with Friedreich's ataxia develop carbohydrate intolerance and 10% develop diabetes mellitus)
Heart disorders (e.g., atrial fibrillation, and resultant tachycardia (fast heart rate) and hypertrophic cardiomyopathy )
It presents before 25 years of age with progressive staggering or stumbling gait and frequent falling. Lower extremities are more severely involved. The symptoms are slow and progressive. Long-term observation shows that many patients reach a plateau in symptoms in the patient's early adulthood.
