TY - JOUR
T1 - Short direct repeats at the breakpoints of a novel large deletion in the CFTR gene suggest a likely slipped mispairing mechanism
AU - Magnani, Carmelina
AU - Cremonesi, Laura
AU - Giunta, Annamaria
AU - Magnaghi, Paola
AU - Taramelli, Roberto
AU - Ferrari, Maurizio
PY - 1996/7
Y1 - 1996/7
N2 - In the cystic fibrosis conductance transmembrane regulator (CFTR) gene a few small deletions and only a large, complex, 50-kb deletion have been described so far. We report a second large deletion, which had been hypothesized in a patient affected by cystic fibrosis on the basis of an abnormal pattern of inheritance of the intragenic microsatellites IVS17b/TA and IVS17b/CA. Southern blot analysis revealed the presence of an anomalous band in the patient and her father, in the region encompassing exons 13-19, approximately 0.6 kb shorten than the one present in normal controls, in addition to the band of the correct size. Cloning and sequencing the DNA fragments spanning the region of interest demonstrated the presence of a 703-bp deletion causing complete removal of exon 17b in the paternal cystic fibrosis chromosome. This analysis revealed the presence of two short direct repeats flanking the breakpoints. The 3' repeat partially overlapped the IVS17b/CA microsatellite and the number of CA repeated units present in the paternal cystic fibrosis allele was the shortest ever found among chromosomes so far analyzed. These data map suggest that the mechanism for the generation of the deletion may have involved a slipped mispairing during DNA replication, which has not previously been described in the CFTR gene.
AB - In the cystic fibrosis conductance transmembrane regulator (CFTR) gene a few small deletions and only a large, complex, 50-kb deletion have been described so far. We report a second large deletion, which had been hypothesized in a patient affected by cystic fibrosis on the basis of an abnormal pattern of inheritance of the intragenic microsatellites IVS17b/TA and IVS17b/CA. Southern blot analysis revealed the presence of an anomalous band in the patient and her father, in the region encompassing exons 13-19, approximately 0.6 kb shorten than the one present in normal controls, in addition to the band of the correct size. Cloning and sequencing the DNA fragments spanning the region of interest demonstrated the presence of a 703-bp deletion causing complete removal of exon 17b in the paternal cystic fibrosis chromosome. This analysis revealed the presence of two short direct repeats flanking the breakpoints. The 3' repeat partially overlapped the IVS17b/CA microsatellite and the number of CA repeated units present in the paternal cystic fibrosis allele was the shortest ever found among chromosomes so far analyzed. These data map suggest that the mechanism for the generation of the deletion may have involved a slipped mispairing during DNA replication, which has not previously been described in the CFTR gene.
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U2 - 10.1007/s004390050167
DO - 10.1007/s004390050167
M3 - Article
C2 - 8682493
AN - SCOPUS:0029977275
VL - 98
SP - 102
EP - 108
JO - Human Genetics
JF - Human Genetics
SN - 0340-6717
IS - 1
ER -