A Dutch study [61] performed on over one hundred SIDS cases evaluated a comprehensive exon screen for cardiac arrhythmia genes (SCN5A, KCNQ1, KCNH2, KCNE1, KCNE2, CACNA1C, CAV3, ANK2 and KCNJ2). This evidence concerns the gene KCNJ2 and chronic obstructive pulmonary disease.