High mutation detection rate in the COL4A5 collagen gene in suspected Alport syndrome using PCR and direct DNA sequencing

• Published in: Journal of the American Society of Nephrology Vol. 9; no. 12; pp. 2291 - 2301
• Main Authors: MARTIN, P, HEISKARI, N, NEUMANN, H, SPRINGATE, J, SHOWS, T, PETTERSSON, E, TRYGGVASON, K, JING ZHOU, LEINONEN, A, TUMELIUS, T, HERTZ, J. M, BARKER, D, GREGORY, M, ATKIN, C, STYRKARSDOTTIR, U
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.12.1998
• Subjects: Amino Acid Substitution; Base Sequence; Biological and medical sciences; Chromosomes, Human, Pair 2 - genetics; Collagen - genetics; DNA Mutational Analysis; Exons - genetics; Female; Frameshift Mutation; Genetic Heterogeneity; Glomerulonephritis; Humans; Introns - genetics; Male; Medical sciences; Medicin och hälsovetenskap; Molecular Sequence Data; Mutation, Missense; Nephritis, Hereditary - classification; Nephritis, Hereditary - genetics; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Point Mutation; Polymerase Chain Reaction; Promoter Regions, Genetic; Protein Isoforms - genetics; RNA Splicing; Sequence Alignment; Sequence Analysis, DNA; Sequence Deletion; Sequence Homology, Nucleic Acid; X Chromosome - genetics; Glomerulonephritis; Kidney disease; Human; Urinary system disease; Exploration; Genetic determinism; Genetic disease; Polymerase chain reaction; Gene; Collagen; DNA; Alport syndrome; Mutation
• ISSN: 1046-6673; 1533-3450
• DOI: 10.1681/asn.v9122291

Approximately 85% of patients with Alport syndrome (hereditary nephritis) have been estimated to have mutations in the X chromosomal COL4A5 collagen gene; the remaining cases are autosomal with mutations in the COL4A3 or COL4A4 genes located on chromosome 2. In the present work, the promoter sequence and previously unknown intron sequences flanking exons 2 and 37 of COL4A5 were determined. Furthermore, intron sequences flanking the other 49 exons were expanded from 35 to 190 to facilitate mutation analysis of the gene. Using this information, all 51 exons and the promoter region were PCR-amplified and sequenced from DNA of 50 randomly chosen patients with suspected Alport syndrome. Mutations were found in 41 patients, giving a mutation detection rate of 82%. Retrospective analysis of clinical data revealed that two of the cases might be autosomal. Although it could not be determined whether the remaining seven cases (14%) were autosomal or X chromosome-linked, it is likely that some of them were autosomal. It is concluded that PCR amplification and direct DNA sequencing of the promoter and exons is currently the best procedure to detect mutations in COL4A5 in Alport syndrome.