title: Single-strand conformational polymorphism and direct sequencing applied to carrier testing in families with ornithine transcarbamylase deficiency.
abstract: Single-strand conformational polymorphism (SSCP) and direct sequencing were used to confirm or deny carrier status in three families with ornithine transcarbamylase (OTC) enzyme deficiency. Two male probands with "late onset" OTC deficiency, whose "private" mutations were previously characterized, inherited the mutations form their heterozygous mothers. One of the heterozygous mothers had a false negative allopurinol test. Three female siblings of the two male probands were tested, one proved to be a carrier of the respective mutation while the other two were found to have normal alleles. In the third family, the proband was a female with "late onset" presentation of OTC deficiency. We found a new point mutation in this girl consisting of a guanine-to-cytosine transversion at nucleotide 520 resulting in a substitution of proline for alanine at amino acid 142 of the mature OTC protein. We confirmed that this mutation occurred spontaneously and that neither of the two parents carries this mutation. We conclude that SSCP, in conjunction with direct sequencing, is a useful technique that can be practically applied for carrier testing in families with OTC deficiency.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis 55455.
authors.forename: M Y
authors.initials: MY
authors.lastname: Tsai
authors.forename: R A
authors.initials: RA
authors.lastname: Holzknecht
authors.forename: M
authors.initials: M
authors.lastname: Tuchman
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis / Q000235:genetics*; D000641:Ammonia / Q000097:blood*; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004277:DNA, Single-Stranded / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D017353:Gene Deletion; D006580:Genetic Carrier Screening / Q000379:methods*; D006801:Humans; D007223:Infant; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009954:Ornithine Carbamoyltransferase / Q000235:genetics*; D020163:Ornithine Carbamoyltransferase Deficiency Disease; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004277:DNA, Single-Stranded; D000641:Ammonia; D009954:Ornithine Carbamoyltransferase