Population Analysis on the Basis of Deduced Haplotypes from Random Families

Prolonged clinically asymptomatic evolution after HIV-1 infection is marked by the absence of complement C4 null alleles at the MHC

“…The antigen frequencies ofthe control population, 126 normal blood donors for ABC, and 104 normal blood donors for C4A, C4B, DR, corresponded to the antigen frequencies for Caucasians as published by Baur et ai [21], except for an overall 5% decrease of Al CW7 B8 DR3 (selection bias of the control population) and an increase of about 5% for A3, B7, DR5 and DR6.…”

Molecular analysis of HLA-DQ A alleles in coeliac disease lack of a unique disease-associated sequence

“…Moreover the A4 allele was shared also by the haplotype DR5/DQw3. Since the DQw2 specificity is also present in 20-30% ofthe Caucasian healthy population (Baur et al, 1984;Corazza era/., 1985), we have studied a group of HLA-D-matched healthy controls. No difference was observed between the hybridization patterns obtained with the four DQ A ASO probes in coeliac patients and HLA-D-matched healthy controls.…”

“…Most coeliac patients, in fact, carry the serological haplotypes DR3-DQw2 and/or DR7-DQw2 (Tosi et al, 1983;Corazza et al, 1985;Tiwari &Terasaki, 1985), whereas patients negative for these haplotypes carry DR4-DQw3 (Tosi et al, 1986), Restriction fragment length polymorphism (RFLP) analysis of HLA-DQ genes has shown that coeliac disease is strongly associated with a DQ A allele (Roep et al, 1988) and with a particular DQ a/P heterodimer, encoded by a combination of DQ A1 *0501 and DQ B1 *0201 alleles (Sollid et al, 1989;Bodmer, Marsh & Albert, 1990), Recently, an association with some DP B alleles has been also reported (Bugawan et al, 1989;Kagnoff e/ at., 1989;Colonna et al, 1990) but it seems to be secondary to that with DQ alleles (Spurkland et al, 1990), In order to elucidate further the genetic association between coeliac disease and HLA-DQ genes, we have analysed by polymerase chain reaction (PCR) amplification the allelic variability ofthe highly polymorphic second exon ofthe HLACorrespondence: Prof, G, R, Corazza, I Patologia Medica, Policlinico S, Orsola, Via Massarenti 9, 40138 Bologna, Italy, DQ Al gene in 20 adult coeliac patients. Since the DQw2 specificity is also present in 20-30% of Caucasian healthy subjects (Baur et at., 1984;Corazza et al, 1985), the results have been compared with those obtained in 20 HLA-D-matched healthy controls. Moreover, by RFLP analysis, we have investigated whether our patients showed the previously reported strong association with a 4 0-kb BglW fragment of a HLA-DQ A allele (Roep et al, 1988),…”

The probability of parentage exclusion based on restriction fragment length polymorphisms

“…The highest values have been found in HLA system; 57.5~ in HLA-A, 80.9~ in HLA-B, 42.6~ in HLA-C, 69.7~ in HLA-DR and 29.5~ in HLA-DQ, which were calculated from allelic frequencies reported in the Ninth International Histocompatibility Workshop (Baur et al, 1984). The next ones would be Gm system with 40.7~ and Gc system with 38.2~.…”

“…Polymorphisms in HLA-leucocyte types (Baur et aL, 1984) and salivary proteins and/or isozymes (Ikemoto et al, 1977) are also of use. Recent advents of recombinant DNA techniques have added another promising marker, that is, restriction fragment length polymorphisms (RFLPs) which have been proved to be polymorphic enough for mapping genetic linkage in man (Botstein et aL, 1980).…”