Screening of Nijmegen breakage syndrome 1 mutations in four unrelated families by polymerase chain reaction using sequence-specific primers

• Published in: Genetic testing Vol. 10; no. 1; p. 24
• Main Authors: Di Masi, Alessandra, Antoccia, Antonio, Spadoni, Emanuela, Varon-Mateeva, Raymonda, Maraschio, Paola, Tanzarella, Caterina
• Format: Journal Article
• Language: English
• Published: United States 01.03.2006
• Subjects: Alleles; Cell Cycle Proteins - genetics; Chromosome Disorders - diagnosis; Chromosome Disorders - epidemiology; Chromosome Disorders - genetics; DNA Mutational Analysis - methods; Exons - genetics; Family; Female; Gene Frequency - genetics; Genes, Recessive; Heterozygote; Humans; Italy; Male; Mass Screening - methods; Mutation; Nijmegen Breakage Syndrome - diagnosis; Nijmegen Breakage Syndrome - epidemiology; Nijmegen Breakage Syndrome - genetics; Nuclear Proteins - genetics; Pedigree; Polymerase Chain Reaction - methods; Prenatal Diagnosis - methods; Sensitivity and Specificity; Italy
• ISSN: 1090-6576
• DOI: 10.1089/gte.2006.10.24

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder characterized by a marked predisposition to lymphoreticular malignancies. The rarity of the disease and the presence, in several cases, of a mild clinical phenotype make diagnosis difficult. The underlying gene, NBS1, consists of 16 exons and encodes nibrin, a member of the hMRE11/hRAD50/hNBS1 protein complex. In addition to the "Slavic mutation," 657del5, identified in more than 100 patients with NBS, 9 other mutations have been found in families of different ethnic origin. We have developed a polymerase chain reaction (PCR) method to rapidly detect the private mutations, 742insGG and 835del4, in exon 7 and the 900del25 mutation in exon 8 of the NBS1 gene. In particular, we designed NBS1-specific primers for wild-type and mutated alleles, and optimized a specific PCR protocol for each mutation. We used this method to analyze 4 unrelated NBS families, 3 from Italy and 1 from Morocco. We believe it could be a useful tool for: (1) confirming the NBS diagnosis in the presence of clinical signs of the disease; (2) identifying NBS heterozygotes and performing prenatal diagnosis in families with affected members; and (3) screening selected populations in which the frequency of NBS might be higher because of a founder effect.