The association of HLA A1, B8, and DR3 with generalized myasthenia gravis (GMG) in Caucasoids is well established, but no particular gene has been implicated and there is still no adequate explanation in functional terms. In this study we have taken advantage of sequential genomic markers between B8 and DR3 so as to map the location of susceptibility gene(s) on the A1, B8, DR3 (8.1) ancestral haplotype. By studying 51 patients, we have delineated a region between HLA B and TNF which is shared by 29/29 patients with B8 and DR3, 19/19 patients with B8 but not DR3 and 2/3 patients with DR3 but not B8. The potential importance of this region was confirmed by examining a similar disease induced by D-Penicillamine (D-PenMG) and associated with different HLA class II alleles (DR1 and/or DR7). Among these patients, 7/16 (44%) have B8, often with other markers of 8.1. These results implicate at least two categories of genes in determining susceptibility to MG; one located in the region between HLA B and TNF may be immunoregulatory, whereas the second, located in the class II region, may relate to the inducing factor (e.g., DR1 or DR7 in D-PenMG).

A panel of simple repetitive oligonucleotide probes has been designed and tested for multilocus DNA fingerprinting in some 200 fungal, plant and animal species as well as man. To date at least one of the probes has been found to be informative in each species. The human genome, however, has been the major target of many fingerprintins studies. Using the probe (CAC) 5 or (GTG) 5 , individualization of all humans is possible except for monozygotic twins. Paternity analyses are now perfonned on a routine basis by the use of multilocus fingerprints, inctuding also cases of deficiency, i.e. where one of the parents is not available for analysis. In forensie science stain analysis is feasible in all tissue remains containing nuc)eated cells. Depending on the degree of DNA degradation a variety of oligonucleotides are informative, and they have been proven useful in actual case work. Advantages in comparison to other methods including enzymatic DNA amplification techniques (PCR) are evident. Fingerprint patterns of tumors may be changed due to the gain or loss of chromosomes and/or intrachromosomal deletion and amplification events. Locus-specific probes were isolated from the human (CAC) 5 /(GTG) 5 fingerprint with a varying degree of informativeness (monomorphic versus truly hypervariable markers). The feasibility of three different approaches. for the isolation of hypervariable mono-locus probes was evaluated. Finally, one particular mixed simple (gt)n(ga)m repeat locus in the second intron of the HLA-DRB genes has been scrutinized to allow comparison of the extent of exon-encoded (protein-) polymorphisms versus intronie bypervariability of simple repeats: adjacent to a single gene sequence (e.g. HLAMDRBl•0401) many different length alleles were found. Group-specific structures of basic repeats were identified within the evolutionarily related DRB alleles. As a further application it is suggested here that due to the ubiquitous interspersion of their targets, short probes for simple repeat sequences are especially useful tools for ordering genomic cosmid, yeast artificial chromosome and phage banks.

We describe a rapid non-radioactive DNA typing of the serological types DR1-DRw10 using polymerase chain reaction (PCR)-amplified DNA and 15 sequence-specific oligonucleotides (SSO) which are labelled enzymatically at their 3' end with one digoxigenin (DIG). The hybridized SSOs were detected using anti-DIG alkaline phosphatase and Fab fragments and visualization was obtained with the chemiluminescent substate 3-(2'-spiroadamantan)-4-(3''-phosphoryloxy)-phenyl-1,2-di o xetan (AMPPD). The results were identical with those of the previously used 5-bromo-4-chloro-3-indolyl-phosphate (BCIP)/4-nitrobluetetrazolium chloride (NBT) system. The use of AMPPD is more rapid and allows the repeated rehybridization of the membrane-bound DNA.

No abstract

A total of 94 patients with juvenile chronic arthritis (JCA) was tested for HLA class I by serology and for class II by RFLP typing. Early onset JCA (EOPA) is associated with HLA-A2, DR5 and DR8 in both males and females. The combination (joint occurrence) of these JCA associated alleles (A2, DR5, DR8) is frequently seen in patients with chronic iridocyclitis. Late onset pauciarticular disease has an increased frequency of HLA-B27, especially in males. Our data confirm that polyarticular JCA with early childhood onset (< or = 4 years) is associated with DR5 and DR8 and has a different immunogenetic background from polyarticular JCA with later childhood (> 4 years) onset (associated with DR4).