title: Detection of large deletion mutations in the COL4A5 gene of female Alport syndrome patients.
abstract: Alport syndrome is the most common form of hereditary nephritis, and the majority of cases are caused by mutations in the COL4A5 gene. However, direct sequencing by polymerase chain reaction (PCR), from genomic DNA, or reverse transcriptase-polymerase chain reaction (RT-PCR), from mRNA, or polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) has reportedly resulted in detection rates of 31% to 84%, but of only 20% to 71% when restricted to female patients. This report concerns two female patients with X-linked Alport syndrome. Although mutational analysis of the COL4A5 gene was conducted with direct sequencing using genomic DNA and mRNA extracted from leukocytes, the results were negative for detection of mutations. Semi-quantitative PCR using genomic DNA was therefore conducted to detect large heterozygous deletions. The results were that the first patient showed complete loss of the COL4A5 gene and the second patient showed deletion from exons 37 to 51. Our patients possessed large heterozygous deletions in the COL4A5 gene that could not be detected with the standard direct sequencing method and were identified with semi-quantitative PCR. Previously reported mutation detection rates for female patients have been lower than overall rates. Our findings indicate that this difference may, in part, be due to failure to detect this type of mutation with conventional analytical methods.
authors.affiliation: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan. nozu@med.kobe-u.ac.jp
authors.forename: Kandai
authors.initials: K
authors.lastname: Nozu
authors.forename: Rafal
authors.initials: R
authors.lastname: Przybyslaw Krol
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Ohtsuka
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Norishige
authors.initials: N
authors.lastname: Yoshikawa
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Nozu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaito
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kanda
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hashimura
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Hamasaki
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Iijima
authors.forename: Masafumi
authors.initials: M
authors.lastname: Matsuo
mesh_terms: D000328:Adult; D041321:Chromosomes, Human, X; D024141:Collagen Type IV / Q000235:genetics* / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D005820:Genetic Testing / Q000379:methods*; D006579:Heterozygote; D006801:Humans; D007668:Kidney / Q000378:metabolism; D009394:Nephritis, Hereditary / Q000235:genetics* / Q000378:metabolism; D018807:Polymorphism, Single-Stranded Conformational; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C478159:COL4A5 protein, human; D024141:Collagen Type IV; D012333:RNA, Messenger