Spinal muscular atrophy with lower extremity predominance 2B (SMALED2B) is a rare neuromuscular disorder characterised by generalised muscle weakness.
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. The disorder is frequently fatal in early childhood.
The disease is caused by a mutation in the BICD2 gene and is passed on in an autosomal dominant manner. There is no known cure to SMALED2B.