Homologous recombination between the LTRs of a human retrovirus-like element causes a 5-kb deletion in two siblings.
The RTVL-H family of human endogenous retrovirus-like elements consists of approximately 1,000 intact members and of a similar number of solitary long terminal repeats (LTRs). In this study, the genetic heterogeneity of these elements has been investigated using unique flanking probes isolated from cDNA clones containing RTVL-H sequences. Four such probes were used to screen a panel of human DNA samples for genetic differences. One of these probes detected a 5.0-kb deletion in two related individuals. Cloning and DNA hybridization analysis indicated that the nondeleted common allele contained an intact RTVL-H element, whereas the deleted variant allele contained only a single LTR. DNA sequence comparisons strongly suggest that the deletion is due to homologous recombination between the 5' and 3' LTRs of the RTVL-H sequence. This is the first reported case of a DNA variation in humans that is due to an LTR-LTR excision event.
Mager
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DL
Terry Fox Laboratory, British Columbia Cancer Research Centre, University of British Columbia, Vancouver, Canada.
Goodchild
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NL
D000483:Alleles; D015139:Blotting, Southern; D002872:Chromosome Deletion; D015342:DNA Probes; D004251:DNA Transposable Elements; D006801:Humans; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000235:genetics*
D015342:DNA Probes; D004251:DNA Transposable Elements