NKX2-5 and coronary artery disorder: The A1443D mutation introduces a negatively charged residue in a position where only noncharged amino acids exist in sarcomeric myosins from mammals, chick, zebrafish, Xenopus, and Caenorhabditis elegans and is predicted to interfere with the interaction between the two molecules of the myosin dimer or with other sarcomeric proteins.29 The frequency of the alleles encoding either L122P (NKX2-5) or A1443D (MYH6) in the CHD and control cohorts is 0.000619.