Detection of RB germline mutations using exon-by-exon heteroduplex analysis compared with SSCP.
OBJECTIVE
To compare heteroduplex analysis with SSCP and to develop a simple and effective method for mutational screening of RB gene.


METHODS
Leukocyte DNA was prepared from 12 unrelated Japanese patients with hereditary retinoblstoma. PCR combined with simultaneous nonisotopic heteroduplex and SSCP analysis was used to screen leukocyte DNA for such mutations, exon-by-exon, without the use of restriction endonuclease digestion. PCR was conducted using 28 pairs of primers flanking all 27 exons and the promoter region of the RB gene, with PCR products ranging from 159bp to 326bp. Mutations were identified by sequencing.


RESULTS
Heterozygous germline mutations were detected in 8 of 12 Japanese patients. The mutations were identified by sequencing as follows: G-->C/acceptor of exon 11, T insertion/codon 389, C-->T/codon 455, 33bp insertion/codon 455 (C decreases GA), G-->T/codon 533, C-->T/codon 579, C deletion/codon 674, and C-->T/codon 787.


CONCLUSIONS
Our results suggest that small RB gene mutations are common. Heteroduplex analysis has advantage over SSCP and they may complement each other for the rapid detection of unknown mutations.
Zhang
Q
Q
Molecular Biology Lab, Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou, China.
Minoda
K
K
D004273:DNA, Neoplasm / Q000235:genetics; D005091:Exons / Q000235:genetics; D016161:Genes, Retinoblastoma; D006801:Humans; D009154:Mutation; D009692:Nucleic Acid Heteroduplexes / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D019572:Retinal Neoplasms / Q000235:genetics*; D012175:Retinoblastoma / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000379:methods
D004273:DNA, Neoplasm; D009692:Nucleic Acid Heteroduplexes