A team of researchers from the University of Montreal set out to find the genomic determinants underlying alcohol and tobacco use.
The researchers identified an area relating to alcohol and tobacco use on chromosome 1, and another area relating to alcohol on chromosome 3. They also uncovered an area relating to smoking on chromosome 4, and found sex-specific loci inside some of those areas.
In each of the 120 families in the study entitled 'Genome-wide Scan for Genomic Determinants of Alcohol and Tobacco Use in French Canadian Families', at least one sibling pair was affected by hypertension (high blood pressure) and dyslipidemia (high lipids levels in the blood).
These variables were important because the excessive use of alcohol and tobacco may cause cardiovascular disorders like hypertension, so finding the genomic determinants behind alcohol and tobacco use may point to novel mechanisms for blood pressure modification by these substances.
Phenotyping for alcohol and tobacco use was conducted using questionnaires. The researchers used a dense map, generated by merging 58000 SNPs (single nucleotide polymorphisms) and 437 microsatellite markers, to identify sex-specific and non-specific linked and associated areas.
The prevalence of alcohol use was found to be 17.3 per cent in females and 38.3 per cent in males, while that of tobacco use was 22.2 per cent in females and 28 per cent in males.
"We have found evidence of linkage and association for several genomic regions harbouring genes with potential pathophysiological functions relating to alcohol and smoking. Our sex specific findings may also play a role in the sex differences related to alcohol and tobacco use," said Majid Nikpay of the Research Centre CHUM, University of Montreal, who is the lead author of the study.