Spinal muscular atrophy with lower extremity predominance 2B

Spinal muscular atrophy with lower extremity predominance 2B (SMALED2B) is a rare neuromuscular disorder characterised by generalised muscle weakness.

Spinal muscular atrophy with lower extremity predominance 2B
Other names	Lower extremity-predominant spinal muscular atrophy type 2B, SMALED2B
Spinal muscular atrophy with lower extremity predominance 2B is inherited in an autosomal dominant manner.
Specialty	Neurology
Symptoms	Generalised severe hypotonia at birth
Usual onset	Infancy
Duration	Lifetime
Causes	Mutations in BICD2 gene
Diagnostic method	Molecular test
Prognosis	Life limiting

Indications

Decreased foetal movement is apparent already before birth. The child is born with a generalised muscle weakness (hypotonia) and contractures resembling arthrogryposis multiplex congenita, respiratory insufficiency, and sometimes facial deformations.^[1][2] The disorder is frequently fatal in early childhood.^[1]

Cause

The disease is caused by a mutation in the BICD2 gene and is passed on in an autosomal dominant manner.^[1] There is no known cure to SMALED2B.

See also

• Spinal muscular atrophies
• Spinal muscular atrophy with lower extremity predominance 1
• Spinal muscular atrophy with lower extremity predominance 2A