DNA compression caused by an upstream point mutation.
We observed an apparent series of insertions and deletions beginning 5 bp downstream of an A-->G silent transition in exon 1 of the tumor necrosis factor receptor 1 gene. The apparent sequence anomaly was observed only in individuals carrying the transition. Formamide gel electrophoresis revealed that the apparent sequence anomaly was due to compression. The compression is plausibly explained by a hairpin in the reaction products in a region of trinucleotide CAG repeats. One should suspect the presence of DNA compression when a series of deletions and insertions follows a single base pair mutation that leads to a series of trinucleotide repeats.
Mayo Clinic/Mayo Foundation, Rochester, MN 55905, USA.
B G
BG
Weinshenker
D D
DD
Hebrink
A M
AM
Gacy
C T
CT
McMurray
D015703:Antigens, CD / Q000235:genetics*; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics; D017931:DNA Primers; D003848:Deoxyguanine Nucleotides / Q000737:chemistry / Q000494:pharmacology; D009690:Nucleic Acid Conformation / Q000187:drug effects; D017354:Point Mutation / Q000235:genetics*; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics*; D047888:Receptors, Tumor Necrosis Factor, Type I
D015703:Antigens, CD; D017931:DNA Primers; D003848:Deoxyguanine Nucleotides; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; C065361:2'-deoxy-7-deazaguanosine triphosphate; D004247:DNA