A specific haplotype at the INS/TH loci confers high susceptibility to IDDM

Journal Article · Thu Sep 01 04:00:00 UTC 1994 · American Journal of Human Genetics

OSTI ID:134200

Doria, A; Lee, J; Warram, J H; Krolewski, A S ^[1]

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1. Harvard Medical School, Boston, MA (United States)

Polymorphism at the insulin locus (INS) have consistently been found to be associated with insulin-dependent diabetes mellitus (IDDM). We investigated whether a combined analysis of the INS locus with the 5{prime} flanking tyrosine hydroxylase (TH) locus increases the specificity of this association. A group of 308 Caucasians (201 IDDM CASES and 107 non-diabetic CONTROLS) were genotyped for the two-allele markers, INS/1127PstI and TH/Rsal, by PCR-DGGE. INS/1127PstI allele 2 was more common in CASES than CONTROLS (0.84 vs. 0.68, p<0.0001). The relative risk of IDDM for homozygotes for this allele (2/2) was 3.3 in comparison with the other genotypes (95% CI 2.0-5.3). Similarly, homozygotes for allele 2 of TH/RsaI, which is in moderate linkage disequilibrium with INS/1127PstI ({Delta} = 0.45), had a relative risk of IDDM of 2.5 (1.6-4.2). By haplotyping individuals for the two markers, INS/1127PstI 2/2 genotypes were subdivided on the basis of their INS-TH haplotypes. The excess of INS/1127PstI 2/2 homozygotes in IDDM cases was mainly contributed by homozygotes for the INS-TH haplotype 22. Thus, among hapotypes carrying INS/1127 PstI allele 2, the INS-TH 22 haplotype is a more specific marker of IDDM risk than the INS-TH 21 haplotype. The association of the INS-TH 22/22 genotype with IDDM was independent of HLA, being similar among carriers and non-carriers of IDDM-predisposing DQ{beta} alleles 0302 and 0201-DR3.

• OSTI ID: 134200
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
BIOLOGICAL MARKERS
DIABETES MELLITUS
GENE MUTATIONS
GENES
GENOTYPE
HYDROXYLASES
INSULIN
PATIENTS
POLYMERASE CHAIN REACTION
RISK ASSESSMENT
STATISTICS
TYROSINE