IMPROVED DETECTION OF THE G1528C MUTATION IN LCHAD DEFICIENCY

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, an auto somal recessive disorder of fatty-acid oxidation, is clinically charac terized by skeletal myopathy, Reye-like syndrome, or sudden unexplaine d infant death. A common mutation, G1528C, has recently been reported. To avoid nonspecific amplification from a ''pseudogene'' and potentia l 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 b y 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, indica ting significant genetic heterogeneity. The G1528C mutation has been f ound on at least one allele in all patients with isolated LCHAD defici ency, suggesting that it is an excellent marker for this disease. This DNA test combined with tandem mass-spectrometric in vitro probe analy sis easily identifies affected individuals and carriers in families wh ich are compound heterozygous for G1528C. (C) 1996 Academic Press, Inc .