BabyScreen+ newborn screening

Gene: BICD2

Red List (low evidence)

SMALED2A is an autosomal dominant form of spinal muscular atrophy characterized by early childhood onset of muscle weakness and atrophy predominantly affecting the proximal and distal muscles of the lower extremity, although some individuals may show upper extremity involvement.

SMALED2B is a severe neuromuscular disorder with onset in utero. Affected individuals show decreased fetal movements and are usually born with congenital contractures consistent with arthrogryposis multiplex congenita (AMC). After birth, they have severe hypotonia and muscle atrophy as well as respiratory insufficiency due to muscle weakness. Some patients may have dysmorphic facial features and/or abnormalities on brain imaging.

Multiple families reported with each type and Drosophila model.

Two individuals reported with bi-allelic variants, likely LoF and a neurodevelopmental disorder.

No specific treatment available for any of these disorders.

Created: 24 Sep 2022, 5:13 a.m. | Last Modified: 24 Sep 2022, 5:13 a.m.

Panel Version: 0.191

Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal

Phenotypes
Spinal muscular atrophy, lower extremity-predominant, 2A, autosomal dominant, MIM# 615290; MONDO:0014121; Spinal muscular atrophy, lower extremity-predominant, 2B, autosomal dominant, MIM# 618291; Neurodevelopmental disorder (MONDO#0700092), BICD2-related

Publications

• 23664116
• 23664119
• 23664120
• 27751653
• 28635954
• 30054298
• 29528393
• 35896821