B A Rybicki — Page 3 | PubMed Health

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Chromosome 6p microsatellite polymorphisms in African-Americans.

Allele frequency distributions were determined for seven microsatellite DNA markers spanning the short arm of chromosome 6 in a population of African-Americans. A total of 196 chromosomes were analyzed. African-Americans differed from reported studies on Caucasians in the number of alleles, allele frequency and predominating alleles. These differences resulted in higher heterozygosity and polymorphic information content for these loci in the African-American population than in Caucasians. Each marker appeared to be in Hardy-Weinberg equilibrium within this population. These results demonstrate the need to determine population-specific allele frequency distributions for polymorphic markers when performing genetic linkage studies in racially defined groups. This study provides gene frequency data for this ethnic group in a region of the genome which has attracted attention as contributing genetic susceptibility to a number of diseases.

Alleles↗

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Occupational exposure to manganese, copper, lead, iron, mercury and zinc and the risk of Parkinson's disease.

A population-based case-control study was conducted in the Henry Ford Health System (HFHS) in metropolitan Detroit to assess occupational exposures to manganese, copper, lead, iron, mercury and zinc as risk factors for Parkinson's disease (PD). Non-demented men and women 50 years of age who were receiving primary medical care at HFHS were recruited, and concurrently enrolled cases (n = 144) and controls (n = 464) were frequency-matched for sex, race and age (+/- 5 years). A risk factor questionnaire, administered by trained interviewers, inquired about every job held by each subject for 6 months from age 18 onward, including a detailed assessment of actual job tasks, tools and environment. An experienced industrial hygienist, blinded to subjects' case-control status, used these data to rate every job as exposed or not exposed to one or more of the metals of interest. Adjusting for sex, race, age and smoking status, 20 years of occupational exposure to any metal was not associated with PD. However, more than 20 years exposure to manganese (Odds Ratio [OR] = 10.61, 95% Confidence Interval [CI] = 1.06, 105.83) or copper (OR = 2.49, 95% CI = 1.06,5.89) was associated with PD. Occupational exposure for > 20 years to combinations of lead-copper (OR = 5.24, 95% CI = 1.59, 17.21), lead-iron (OR = 2.83, 95% CI = 1.07,7.50), and iron-copper (OR = 3.69, 95% CI = 1.40,9.71) was also associated with the disease. No association of occupational exposure to iron, mercury or zinc with PD was found. A lack of statistical power precluded analyses of metal combinations for those with a low prevalence of exposure (i.e., manganese, mercury and zinc). Our findings suggest that chronic occupational exposure to manganese or copper, individually, or to dual combinations of lead, iron and copper, is associated with PD.

Age Factors↗