Genomic organisation and chromosomal localisation of two members of the KCND ion channel family, KCND2 and KCND3

To follow a candidate gene approach for the involvement of the KCND2 and KC ND3 genes (Kv4.2 and Kv4.3) in the pathogenesis of the long QT syndrome (LQ TS) and Brugada syndrome, it is necessary to determine the genomic organisa tion of KCND2 and KCND3. We therefore resolved the intron-exon boundaries a nd flanking intronic sequences and found that KCND2 consisted of six exons and KCND3 of seven exons. Subsequently, we designed the oligonucleotide pri mers needed for amplifying the coding exons of both KCND2 and KCND3 and est ablished conditions for polymerase chain reaction amplification of each exo n from genomic DNA. Further-more, the chromosomal localisation of KCND2 and KCND3 was determined as 7q31 and 1p13.2, respectively. This information sh ould facilitate the systematic screening of KCND2 and KCND3 exons for mutat ions in (inherited) arrhythmia syndromes, such as LQTS and Brugada.