Spinal muscular atrophy with lower extremity predominance 2B

Spinal muscular atrophy with lower extremity predominance 2B
Other namesLower extremity-predominant spinal muscular atrophy type 2B, SMALED2B
Autosomal dominant - en.svg
Spinal muscular atrophy with lower extremity predominance 2B is inherited in an autosomal dominant manner.
SymptomsGeneralised severe hypotonia at birth
Usual onsetInfancy
CausesMutations in BICD2 gene
Diagnostic methodMolecular test
PrognosisLife limiting

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.[1][2] The disorder is frequently fatal in early childhood.[1]


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


  1. ^ a b c Online Mendelian Inheritance in Man (OMIM): 618291
  2. ^ Koboldt, Daniel C.; Kastury, Rama D.; Waldrop, Megan A.; Kelly, Benjamin J.; Mosher, Theresa Mihalic; McLaughlin, Heather; Corsmeier, Don; Slaughter, Jonathan L.; Flanigan, Kevin M.; McBride, Kim L.; Mehta, Lakshmi (2018). "In-frame de novo mutation in BICD2 in two patients with muscular atrophy and arthrogryposis". Cold Spring Harbor Molecular Case Studies. 4 (5): a003160. doi:10.1101/mcs.a003160. ISSN 2373-2865. PMC 6169820. PMID 30054298.

Media files used on this page

Autosomal dominant - en.svg
Author/Creator: Domaina, Licence: CC BY-SA 3.0
Autosomal dominant - genetics (english version)
Author/Creator: File:Chromosome-upright.png Original version: Magnus Manske, this version with upright chromosome: User:Dietzel65Vector: derivative work Tryphon, Licence: CC-BY-SA-3.0
Scheme of a Chromosome. (1) Chromatid. One of the two identical parts of the chromosome after S phase. (2) Centromere. The point where the two chromatids touch, and where the microtubules attach. (3) Short (p) arm (4) Long (q) arm. In accordance with the display rules in Cytogenetics, the short arm is on top.