Heteroduplex analysis detects frameshift and point mutations in patients with acute intermittent porphyria

• Published in: Human genetics Vol. 96; no. 2; pp. 161 - 166
• Main Authors: SCHREIBER, W. E, FENTON FONG, NASSAR, B. A, AZIM JAMANI
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-08-1995; Berlin; New York, NY
• Subjects: Base Sequence; Biological and medical sciences; Cloning, Molecular; Errors of metabolism; Exons - genetics; Frameshift Mutation; Genetic Testing - methods; Humans; Hydroxymethylbilane Synthase - genetics; Medical sciences; Metabolic diseases; Molecular Sequence Data; Nucleic Acid Heteroduplexes; Point Mutation; Polymerase Chain Reaction; Porphyria, Acute Intermittent - enzymology; Porphyria, Acute Intermittent - genetics; Proteins and glycoproteins; Sequence Analysis, DNA; Human; Porphyria; Photosensitivity; Skin disease; Enzyme; Metabolic diseases; Lyases; Enzymopathy; Carbon-nitrogen lyases; Genetic disease; Hydroxymethylbilane synthase; Ammonia-lyases; Gene; Porphyrin; Pigments; Genetics; Mutation; Detection
• ISSN: 0340-6717; 1432-1203
• DOI: 10.1007/BF00207373

We used heteroduplex analysis to screen for mutations in the porphobilinogen deaminase gene in 21 patients with acute intermittent porphyria (AIP). Unique banding patterns were investigated by direct sequencing of polymerase chain reaction products and, when indicated, sequencing of cloned DNA containing the exon of interest. Two frameshift mutations were found, a 2-bp deletion in exon 5 and a 1-bp insertion in exon 7. Both mutations generate a premature stop codon. Two point mutations, in exons 10 and 14, were also observed. The C-->T mutation in exon 10 codes for an Arg173 to Trp substitution, while a G-->A mutation in exon 14 changes Trp283 into a premature stop codon. This study extends the spectrum of mutations that cause AIP and demonstrates the utility of heteroduplex analysis as a screening technique.