0000000000799229
AUTHOR
J. Bertrams
Biostatistical basis of individualization and segregation analysis using the multilocus DNA probe MZ 1.3: results of a collaborative study.
A collaborative study using the multilocus minisatellite DNA probe MZ 1.3 was carried out to investigate segregation information, mutation rate, DNA fragment frequencies as well as band sharing characteristics. The fingerprint patterns of 393 children as well as 694 unrelated individuals were analysed after digestion of DNA with the restriction enzyme HinfI. A mutation rate of 1% per meiosis or 0.04% per band was found with a mean number of 26 bands/individual. It was shown that maternal and paternal fragments are inherited in equal proportions. Population frequencies of restriction fragments demonstrated a distribution with increasing frequencies in the small fragment size range below 10 k…
Autoantibodies to the islet antigen ICA69 occur in IDDM and in rheumatoid arthritis.
Islet cell antigen (ICA) 69 is a newly-recognized islet cell antigen to which autoantibodies have been observed in prediabetic relatives of patients with insulin-dependent-diabetes mellitus (IDDM). Here we extend the earlier analysis of ICA69 antibodies to patients with recent-onset IDDM and to patients with other immune-mediated diseases. ICA69 antibodies were determined by Western blot using an affinity purified recombinant fusion protein of ICA69 and maltose binding protein. ICA69 antibody quantities were determined as titres using a titration curve of a standard serum as reference. Mean logarithmic ICA69 antibody titres were 3.4 (+/- 1.4) in 99 patients with acute IDDM compared to 2.8 (…
Null alleles of human complement C4. Evidence for pseudogenes at the C4A locus and for gene conversion at the C4B locus
The two genes for the C4A and C4B isotypes of the fourth component of human complement are located in the MHC class III region. Previous studies have demonstrated the unusual expression of C4 genes in the form of aberrant or duplicated haplotypes. Null alleles of C4A or C4B (AQ0 or BQ0) have been defined by the absence of gene products and occur at frequencies of 0.1-0.3. However, only some C4 null alleles are due to gene deletions, the remainder were thought to be nonexpressed genes. We have analyzed the C4 gene structure of 26 individuals lacking either C4A or C4B protein. The DNA of individuals with apparently nonexpressed C4 genes was tested for the presence of C4A- and C4B-specific seq…
Restriction fragment polymorphisms of the HLA-DR, HLA-DQ, and insulin gene regions in IDDM: The GAW5 data
The primary aim of the insulin-dependent diabetes mellitus (IDDM) component of Genetic Analysis Workshop 5 (GAW5) was to collect and analyze new data on DNA polymorphisms closely linked to the HLA-D region and the insulin gene. The probes and restriction enzymes described here were used by all ten participating labs, and the data from Southern blotting were interpreted and reported according to conventions developed for the Workshop. These DNA data on members of 94 families with two or more IDDM sibs constitute the largest such sample available. The data were used in most of the analyses presented at the Workshop meeting, and are available on request.
Genetic analysis of IDDM: The GAW5 multiplex family dataset
In a collaborative effort by 12 centers from Europe and North America, data were assembled from 94 multiplex families with insulin-dependent diabetes mellitus (IDDM) for analysis of genetic and other factors of possible etiological importance. The dataset contains information on the following genetic markers: HLA-DR beta and -DQ beta restriction fragment length polymorphisms (RFLPs), three RFLPs detected with two probes that map 5' to the insulin gene, the serologically defined HLA loci, and the immunoglobulin allotypes. Data also were included for auto-antibodies to insulin and pancreatic islet cells as possible indicators of pathogenesis and for antibodies to certain viruses that have bee…