Automated mutation screening using dideoxy fingerprinting and capillary array electrophoresis

The rapid progress in the isolation of genes associated with human disease has resulted in an increasing demand for mutation screening methods. The mo lecular diagnosis of the long QT syndrome (LQTS), a cardiac disorder charac terized by prolongation of the QT, interval in the ECG, syncopes, and sudde n death, requires mutation screening of all exons in at least five genes, e ncoding cardiac Na+ and K+ channel subunits. A method for automated dideoxy fingerprinting (ddF) using capillary array electrophoresis (CAE) was devel oped and the efficiency of the method was tested by analyzing 24 DNA sample s with mutations in one of the genes KCNQ1 and KCNH2, which are involved in 50% of LQTS cases. One of these mutations, 362insQK in KCNQ1, is novel. Th e sensitivity was 100% using a single electrophoresis temperature of 18 deg reesC or 25 degreesC. However, analysis of the samples in both the sense an d anti-sense direction were required for high sensitivity. Analysis in a si ngle direction resulted in a decrease of the sensitivity to 74% and 70%, re spectively. The throughput of the ddF method, if performed with a 16 capill ary CAE instrument, is 288 samples per seven hr if each sample is analyzed on both strands. Hum Mutat 18:451-457, 2001. (C) 2001 Wiley-Liss, Inc.