Analysis of case-parent trios at a locus with a deletion allele: association of GSTM1 with autism

BACKGROUND: Certain loci on the human genome, such as glutathione S-transferase M1 (GSTM1), do not permit heterozygotes to be reliably determined by commonly used methods. Association of such a locus with a disease is therefore generally tested with a case-control design. When subjects have already been ascertained in a case-parent design however, the question arises as to whether the data can still be used to test disease association at such a locus. RESULTS: A likelihood ratio test was constructed that can be used with a case-parents design but has somewhat less power than a Pearson's chi-squared test that uses a case-control design. The test is illustrated on a novel dataset showing a genotype relative risk near 2 for the homozygous GSTM1 deletion genotype and autism. CONCLUSION: Although the case-control design will remain the mainstay for a locus with a deletion, the likelihood ratio test will be useful for such a locus analyzed as part of a larger case-parent study design. The likelihood ratio test has the advantage that it can incorporate complete and incomplete case-parent trios as well as independent cases and controls. Both analyses support (p = 0.046 for the proposed test, p = 0.028 for the case-control analysis) an association of the homozygous GSTM1 deletion genotype with autism

Assessment of agricultural assistance for smallholder farmers with their issues and concerns

International audienceGlobally, smallholder farmers only have less than 2 hectares of land but they are crucial to food security. The problem is, they always remain poor. Using focus group discussion (FGD), the study investigated issues and concerns. Results showed that the farmers have received a number of various kinds of assistance from the government which provided them with benefits however they also have sentiments about some matters. The study found that they are highly incapable of addressing many issues surrounding them. Improving their agricultural productivity and household-level income are the main factors in reducing poverty