Michael J. Hobart

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Five polymorphisms in the C6 and C7 genes have been investigated in seven ethnic groups. The allele frequencies are broadly similar in most groups except C7 M/N which is monomorphic in our group of Africans, and C6 MspI and C7 S367T where the allele frequencies in African and Cape Coloured subjects are very different from the other ethnic groups. There is(More)
The terminal components of the complement system (C6-C9) are related proteins, differing in size and complexity. They seem to be typical mosaic proteins, composed of modules which are homologous with parts of other proteins. Individual elements in a mosaic protein are often bounded by introns in the gene, and where they are duplicated within a polypeptide,(More)
Combined subtotal deficiency of C6 and C7, in which both proteins are expressed at very low levels, has been observed in homozygous form in two families. A defect at the 5' splice donor site of intron 15 of the C6 gene explains the low molecular weight of the C6 protein and is probably responsible for its low expressed concentration. The C7 defect is more(More)
The molecular basis of C7 deficiency has been investigated in two Irish families and a number of Israeli families of Moroccan Sephardic Jewish origin. Exon PCR and sequencing revealed a heterozygous point mutation at the 3' splice acceptor site of intron 1 in one Irish family. In the other Irish family, exons 7 and 8 failed to amplify and they were shown to(More)
The linked C6 and C7 loci are rich in genetic markers, both at the protein and DNA levels. There are now seven common DNA polymorphisms distributed over about 300 kbp of chromosome 5p12-14. We report a new TaqI RFLP for C7 and a method for typing a C7 variant (T368S) hitherto known only from cDNA clones. We have re-investigated the published RFLPs to(More)
We report a new polymorphism in the complement C7 gene that results from an A-C transversion in intron 12, 27 bp upstream of exon 13 (C712.-27) and 36 bp upstream of the point mutation that underlies the C7 M/N antigenic polymorphism. The C7 12.-27 polymorphism subdivides C7 M haplotypes, but not C7 N. It also sheds light on the evolution of the various(More)