Improved detection of the G1528C mutation in LCHAD deficiency

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, an autosomal recessive disorder of fatty-acid oxidation, is clinically characterized by skeletal myopathy, Reye-like syndrome, or sudden unexplained infant death. A common mutation, G1528C, has recently been reported. To avoid nonspecific amplification from a "pseudogene" and potential complications, we have developed a nested PCR/PstI digestion method. Here, we report mutation studies in 11 additional unrelated patients with LCHAD deficiency. Genomic DNA fragments (117 bp) were amplified by the nested PCR, digested with PstI, and subjected to electrophoresis on 12% polyacrylamide gel. Four patients were found to be homozygous for the G1528C mutation; 7 patients were compound heterozygous, indicating significant genetic heterogeneity. The G1528C mutation has been found on at least one allele in all patients with isolated LCHAD deficiency, suggesting that it is an excellent marker for this disease. This DNA test combined with tandem mass-spectrometric in vitro probe analysis easily identifies affected individuals and carriers in families which are compound heterozygous for G1528C.