15 6 Abstracts

B-9.1 #299

GENERIC DRB ALLELE TYPING BY PCR-SSOP: AN APPROACH TO RESOLVE IDENTITY IN FORENSIC SAMPLES WITH UNINFORMATIVE DQA1 ALLELE TYPING. JJ Yunis(1,2), MB Delgado(1), JM Williamson(2), EJ Yunis(1,2) and DH Bing(2). I) Division of Immunogenetics, Dana-Farber Cancer Institute, Department of Pathology, Harvard Medical School, Boston MA, USA. 2) The Center for Blood Research, Boston, MA, USA.

The development of the PCR methodology combined to hybridization with sequence specific oligonucleotide probes has allowed the analysis of MHC class II gene polymorphisms for the selection of donor-recipient pairs for organ transplantation, disease association, and population studies. An additional application for this technology has been forensic science where DQAI allele typing (DQ alpha Amplitype kit, Perkin Elmer) has been used as a tool to determine identity in forensic evidence. The DQA Amplitype kit detects 6 out of the I0 DQA1 alleles and 21 phenotypes. Based on the limited polymorphism of the DQAI locus, it is possible that identical typing results could be obtained for two samples. In addition, due to the linkage disequilibrium between DQA1 and DRB alleles, it could be expected that samples with identical DQA1 alleles, have different DRBI alleles. We have used DRB generic PCR amplification followed by hybridization with a panel of twelve DRBI-SSO probes representing the major generic DRB1 alleles to achieve discrimination in two forensic cases were the DQAI typings (DQ alpha Amplitype kit, Perkin Elmer) were not informative. Case #I: A female victim (F1) was typed as HLA-DQA2/DQA4. Two suspects ($1 and $2) were typed as DQA1 .I/DQA4. Case # 2: A female victim (F2) and Two Suspects ($3 and $4) were typed. The victim's HLA-DQA type was identical to that detected in the $3 suspect (DQA2/DQA3). The DRB1 allele typing are given below. Case#1 DRB-SSO reactivity DRBI* Case #2 DRB-SSO ReactivityDRBl* $1 1001, 1005, 1200 01/12 $3 1003, 1006 06/07 $2 1001, 7004, 1003 01/03 $4 1001 01 F1 5703, 1006, 1003 11/07 F2 1004, 1006 04/07 F1/Ep 1001, 7004, 1003 01/03 F2/Ep 1004, 1006 04/07 F1/Sp 1001, 7004, 1003 01/03 F2/Sp 1003, 1006 06/07 Our results indicated that discrimination in forensic evidence can be achieved by using a small panel of SSO probes to type DRB1 alleles and that due to the polymorphism of the DRB1 locus it may represent a better system to determine identity in forensic evidence.

B-9.1 #300

Mhc-DPB DIVERSITY IN PRIMATES. Erik Rozemuller 1, Ronald Bontrop ~, Leone Versluis 1, Marcel Tilanus t, t.Diagnostic DNA laboratory, Academic Hospital Utrecht, The Netherlands. 2.TNO Institute of Applied Radiobiology and Immunology (ITRI), Rijswijk, The Netherlands.

Mhc-DPB polymorphism in non-human primates is studied using sequence based typing (SBT), which was developed for high resolution HLA-DPB1 typing. We performed SBT to 16 DNA samples of rhesus macaques including 7 homozygous typing cells (HTC) and a family. 4 different homozygons sequences could be identified which are defined as allele sequences. 5 additional allele sequences could be deduced by subtraction of homozygous sequences from heterozygous sequences. Detailed analysis of the segregation of Mhc-DPB in the family of rhesus macaques reveals that the analysis of heterozygous sequences is concordant with the Mendelian segregation. The Mamu-DPB allele sequences showed a high degree of similarity with the ItLA-DPB1 consensus. The large number of allele sequences identified after sequencing a limited number of rhesus monkey DNAs, suggests that Mhc-DPB is more polymorphic in rhesus monkeys than in humans. Additionally to the Mamu-DPB sequences, two Patr-DPB sequences were obtained performing SBT to 2 chimpanzee derived DNA samples. The HL~-DPB1 consensus shows a higher degree of similarity with the Patr-DPB sequences than with the Mamu-DPB sequences. This may reflect the different divergence times between the species from a shared ancestor.