FOR NOVEL GENE-MUTATIONS IN 5 JAPANESE MALE-PATIENTS WITH NEONATAL ORLATE-ONSET OTC DEFICIENCY - APPLICATION OF PCR-SINGLE-STRAND CONFORMATION POLYMORPHISMS FOR ALL EXONS AND ADJACENT INTRONS

Ornithine transcarbamylase deficiency (OTC), the most common inborn er ror of the urea cycle, shows an X-linked inheritance with frequent new mutations. Southern blots reveal only a small percent of the mutation , but amplification of cDNA or genomic DNA using the polymerase chain reaction (PCR) followed by DNA sequencing, has contributed greatly to overcoming this difficulty. Problems remaining are the limited availab ility of fresh liver samples for preparation of intact mRNA in the for mer case, and there are primer sequences for PCR for only some exons i n the latter case. Here, we report the structures of intron sequences which are long enough to analyze all exons and adjacent introns of the OTC gene using PCR and PCR single-strand conformation polymorphisms ( PCR-SSCP). We carried out a DNA analysis of findings in five Japanese male patients with neonatal or late onset form. Five patients had muta tions in the protein coding region. C to G (S192R), A to T (D196V), A to G (T264A), T to C (M268T), and C to T (R277W) substitutions. The fi rst four of these were novel missense mutations and the presence of th e mutation was confirmed in the corresponding families.