Genetic mapping on chromosome 20 near the MODY gene: Is there suppression of recombination?

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

OSTI ID:134033

Howard, T D; Rothschild, C B; Bowden, D W ^[1]

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1. Wake Forest Univ., Winston-Salem, NC (United States); and others

Maturity onset diabetes of the young (MODY) is a rare, autosomal dominant form of non-insulin-dependent diabetes mellitus. We are evaluating a chromosome 20-linked form of MODY in a large, well-characterized pedigree known as the R-W family. DNA from 97 family members, including spouses, have been genotyped with nine microsatellite markers and four RFLPs from 20q12-13.1. The highest likelihood order of loci in this 9.8 cM (sex-average) interval is: cen-ADA-D20S119-D20S17-PPGB-D20S178-D20S197-D20S213-D20S16A-D20S22-D20S16B-qter. Two polymorphic loci separable by recombination comprise D20S16 (called A and B here). The highest twopoint LOD scores were observed with D20S16 (Zmax = 17.0, {theta} = 0.001) and ADA (Zmax = 16.4, {theta} = 0.001). Multipoint analysis limits MODY to a sex-average interval of approximately 10 cM (calculated from CEPH family data) defined by ADA and D20S16. The maximum multipoint LOD score observed in this region was 17.22. No recombination events have been observed within this 10 cM interval in affected individuals. The probability of this occurring by chance is P = (1-{theta}){sup n}, where n = number of meioses. With the present data there are 57 (equivalent) informative meioses, so the probability of finding no recombination within the 10 cM inteval is 0.002. In the R-W family, however, there is a 3:1 ratio of male:female meioses. When this is taken into consideration, and the sex-specific genetic distances are used (15.9 cM for female map, 6.8 cM for male map), the probability of observing no recombination in this region is still quite low: P = 0.004, suggesting the possibility that recombination is suppressed in this family.

• OSTI ID: 134033
• 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
AGE DEPENDENCE
BIOLOGICAL MARKERS
DIABETES MELLITUS
DOMINANT MUTATIONS
GENE RECOMBINATION
GENES
GENETIC MAPPING
GENETICS
GENOTYPE
HEREDITARY DISEASES
HUMAN CHROMOSOMES
MEIOSIS
PATIENTS
PROBABILITY
RFLPS
SEX DEPENDENCE
STATISTICS