A novel microsatellite polymorphism in the human OB gene: a highly polymorphic marker for linkage analysis

Area of Science:

• Genetics and Genomics
• Human Molecular Genetics
• Disease Association Studies

Background:

• The mouse ob gene and its human homologue OB are linked to obesity.
• Understanding the human OB gene's role in disease requires informative genetic markers.
• Previous research lacked suitable markers for studying the human OB gene.

Purpose of the Study:

• To identify novel, highly polymorphic genetic markers within the human OB gene.
• To establish the location of a new marker relative to the OB gene.
• To assess the marker's utility in linkage studies for obesity and related metabolic disorders.

Main Methods:

• Screened the human OB gene's genomic sequence for simple tandem repeat polymorphisms.
• Identified and characterized a novel tetranucleotide repeat in the 3' flanking region.
• Performed two-point linkage mapping in Centre Etude Polymorphisme Humaine (CEPH) families.

Main Results:

• A highly informative tetranucleotide repeat marker with 15 alleles and high heterozygosity (0.85) was identified.
• The marker was mapped to the same chromosomal interval as the OB gene (between D7S514 and D7S530).
• No significant allele frequency differences were observed between non-insulin-dependent diabetes mellitus (NIDDM) patients and controls, but a trend towards higher body weight was noted in controls with a specific genotype.

Conclusions:

• The novel tetranucleotide repeat marker is highly polymorphic and located near the human OB gene.
• This marker is valuable for future linkage studies investigating the OB gene's association with obesity, NIDDM, hypertension, and insulin resistance syndrome.
• Further research is warranted to explore genotype-phenotype correlations.