Mutations in the @entity14050 gene are responsible for the @entity74 @entity1129 ( @entity1129 ). Many different mutations have been identified using various techniques, with detection efficiencies ranging from 57 to 85%. In this study, we employed short tandem repeat (STR) haplotypes to enhance mutation identification in 55 unrelated @entity1129 families of Iberian origin (20 Spanish, 17 Brazilian, and 18 Hispanic-American); we were able to identify 95% of the expected mutations. Allelic sizes were standardized based on a reference sample (CEPH 1347-2). Subsequent mutation screening was performed by PTT, SSCP, and DHPLC, and abnormal regions were sequenced. Many STR haplotypes were found within each population and six haplotypes were observed across several of these populations. Single nucleotide polymorphism (SNP) haplotypes further suggested that most of these common mutations are ancestrally related, and not hot spots. However, two mutations ( @entity69667 and @entity69668 ) may indeed be recurring mutational events. Common haplotypes were present in 13 of 20 Spanish @entity1129 families (65%), in 11 of 17 @entity1129 families (65%), and, in contrast, in only eight of 18 Hispanic-American families (44%). Three mutations were identified that would be missed by conventional screening strategies. In all, 62 different mutations (28 not previously reported) were identified and their associated haplotypes defined, thereby establishing a new database for @entity1129 families, and extending the spectrum of worldwide @entity14050 mutations.

Independent mutational events are rare in the XXXX gene: haplotype prescreening enhances mutation detection rate.

@entity14050 :: ('472', 'Gene') :: ['ATM'] @entity74 :: ('MESH:D030342', 'Disease') :: ['autosomal recessive disorder'] @entity1129 :: ('MESH:D001260', 'Disease') :: ['Brazilian A-T', 'A-T', 'Iberian A-T', 'ataxia-telangiectasia'] @entity69667 :: ('c|SUB|C|8977|T', 'DNAMutation') :: ['8977C>T'] @entity69668 :: ('c|DEL|8264_8268|ATAAG', 'DNAMutation') :: ['8264_8268delATAAG']
@entity14050 :: (472,Gene) :: ['ATM']
