[The long QT syndrome from the bedside to molecular genetic laboratory. The history of the first described Hungarian family].

The authors demonstrate the developments of molecular genetic methods on the example of the first described Hungarian family suffering from inherited long QT (Romano-Ward) syndrome. The family belonged to the LQT2 subgroup according to both the clinical picture and the results of different molecular genetic methods from linkage mapping to sequencing. The final result of sequencing showed a missense mutation, affecting codon 568 in exon 7 of the KCNH2 (HERG) gene, leading to a tryptophan-cysteine change in the amino acid chain.