FAQs about X-linked infantile spinal muscular atrophy
X-linked infantile spinal muscular atrophy (XL-SMA) is a rare form of spinal muscular atrophy that occurs only in male infants, and is generally fatal before the age of 2 years. It is characterized by muscle weakness, difficulty breathing, misshapen joints, and broken bones, often before birth.
Due to the way XL-SMA is inherited, girls do not show symptoms but are genetic carriers of the mutated gene which causes the condition.
At this point, there is no cure for XL-SMA. Instead, treatment is supportive.
A child with XL-SMA will be born with certain characteristics, which may include misshapen joints and broken bones, along with muscle weakness and difficulty breathing. Diagnosis includes a physical examination of the infant after birth, a family history of any X-linked inherited disorders, and tests including imaging and a blood test for genetic testing.
No, adults cannot develop XL-SMA. Only male infants with a mutated ubiquitin-like modifier activating enzyme 1 (UBA1) gene can have the condition, and the life expectancy sees most male children with the condition die before the age of 2 years.