Two out of 47 patients with sporadic tetralogy of Fallot (TOF), the most common cyanotic conotruncal heart defect (CTD), showed heterozygous missense mutations of the ZFPM2/FOG2 gene. Knockout mice carrying mutations in the ZFPM2/FOG2 gene have similarly been found to exhibit TOF. While both mutant ZFPM2/FOG2 proteins, E30G (c.88A>G) and S657G (c.1968A>G), retain the ability to bind the partner protein GATA4 and repress GATA4 mediated gene activation, the S657G, but not the E30G, mutation is subtly impaired in this function. ZFPM2/FOG2 gene mutations may contribute to some sporadic cases of TOF.

FIGURE 3. The E30S and S657G mutations do not signi¢cantly impair binding to the partner protein GATA4. A: GST pull-down assay showing retention of wild-type ZFPM2/FOG2, the E30S and S657G mutants by GATA4 N-¢nger. Input lanes show that equivalent amounts of wild-type and mutant ZFPM2/FOG2 proteins were used. B: Coomassie-stained gel indicating that approximately equal amounts of GST-GATA4 N-¢nger and GSTwere used in the pull-down assay.

The high mutation rate at the NF1 locus results in a wide range of molecular abnormalities. The majority of these mutations are private and rare, generating elevated allelic diversity with a restricted number of recurrent mutations. In this study, we have assessed the efficacy of denaturing high-performance liquid chromatography (DHPLC), for detecting mutation in the NF1 gene. DHPLC is a fast and highly sensitive technique based on the detection of heteroduplexes in PCR products by ion pair reverse-phase HPLC under partially denaturing conditions. We established theoretical conditions for DHPLC analysis of all coding exons and splice junctions of the NF1 gene using the WAVEmaker software version 4.