X-linked spinal muscular atrophy 2

A spinal muscular atrophy characterized by neonatal onset of severe hypotonia, areflexia, and multiple congenital contractures associated with loss of anterior horn cells and infantile death that has_material_basis_in hemizygous mutation in the UBA1 gene on ch

A spinal muscular atrophy characterized by neonatal onset of severe hypotonia, areflexia, and multiple congenital contractures associated with loss of anterior horn cells and infantile death that has_material_basis_in hemizygous mutation in the UBA1 gene on chromosome Xp11.3.

Signs and symptoms

• Elevated circulating creatine kinase activity
• Hypotonia
• Tongue fasciculations
• Myopathic facies
• Areflexia
• Persistent head lag
• Decreased compound muscle action potential amplitude
• Weak cry
• Facial palsy
• Inguinal hernia

Also known as: SMAX2; X-linked distal arthrogryposis multiplex congenita; X-linked spinal muscular atrophy type 2; infantile-onset X-linked spinal muscular atrophy; spinal muscular atrophy with arthrogryposis