CAP2: a new gene responsible for nemaline myopathy

American researchers have identified, for the first time, a pathogenic variant of the CAP2 gene present in a heterozygous state in a sporadic form of nemaline myopathy. The child presented with neonatal onset hypotonia and, above all, very severe dilated cardiomyopathy: 

  • the CAP2 gene encodes a cyclase-binding protein (cyclase-associated-protein type 2),
  • functional studies have confirmed the involvement of this new gene both in terms of the amount of protein and the mRNAs produced,
  • a mouse model invalidated for this gene presented a muscular and cardiac phenotype similar to that of the child,
  • his parents were healthy carriers of the variant and had no heart disease,
  • the child underwent a heart transplant when he was one year old.

This gene enriches the already long list of genes involved in nemaline myopathies.


A homozygous CAP2 pathogenic variant in a neonate presenting with rapidly progressive cardiomyopathy and nemaline rods. Gurunathan S, Sebastian J, Baker J, et al. Am J Med Genet A. 2021 Dec 4.