Genome-wide association studies (GWAS) of complex, heritable, behavioral phenotypes have yielded an incomplete accounting of the genetic influences. The identified loci explain only a portion of the observed heritability, and few of the loci have been shown to be functional. It is clear that current GWAS techniques overlook key components of phenotypically relevant genetic variation, either because of sample size, as is frequently asserted, or because of methodology. Here we use arginine vasopressin receptor 1a (AVPR1a) as an in-depth model of a methodologic limitation of GWAS: the functional genetic variation (in the form of short tandem repeats) of this key gene involved in affiliative behavior cannot be captured by current GWAS methodologies. Importantly, we find evidence of differential allele expression, twofold or more, in at least a third of human brain samples heterozygous for a reporter SNP in the AVPR1a transcript. We also show that this functional effect and a downstream phenotype, externalizing behavior, are predicted by AVPR1a STRs but not SNPs.

Most HIV-infected children in Sub-Saharan Africa are born where programs for the prevention of mother-to-child transmission of HIV (PMTCT) exist but are not universally operational. The expansion of PMTCT programs in Cameroon was among the largest in francophone Africa, but despite highly variable estimates of PMTCT uptake (ranging from 20% to 66%), it is clear that not enough HIV-infected pregnant Cameroonian women benefit from treatment to prevent HIV transmission to their children. The reasons why HIV-infected women in Cameroon do not use treatments to prevent this transmission remain partially unidentified. We conducted a qualitative study of the therapeutic itineraries (treatments taken and motivations) followed by HIV-infected pregnant women in Cameroon to understand the barriers to accessing high-quality PMTCT care. Here we construct the therapeutic itinerary for HIV-infected pregnant women, and identify the barriers at each step. Lack of financial independence, personal support, and empowering information were the primary obstacles at multiple steps.