BACKGROUND Peripartum cardiomyopathy shares some clinical features with idiopathic dilated cardiomyopathy, a disorder caused by mutations in more than 40 genes, including TTN, which encodes the sarcomere protein titin. METHODS In 172 women with peripartum cardiomyopathy, we sequenced 43 genes with variants that have been associated with dilated cardiomyopathy. We compared the prevalence of different variant types (nonsense, frameshift, and splicing) in these women with the prevalence of such variants in persons with dilated cardiomyopathy and with population controls. RESULTS We identified 26 distinct, rare truncating variants in eight genes among women with peripartum cardiomyopathy. The prevalence of truncating variants (26 in 172 [15%]) was significantly higher than that in a reference population of 60,706 persons (4.7%, P = 1.3×10−7) but was similar to that in a cohort of patients with dilated cardiomyopathy (55 of 332 patients [17%], P = 0.81). Two thirds of identified truncating variants were in TTN, as seen in 10% of the patients and in 1.4% of the reference population (P = 2.7×10−10); almost all TTN variants were located in the titin A-band. Seven of the TTN truncating variants were previously reported in patients with idiopathic dilated cardiomyopathy. In a clinically well-characterized cohort of 83 women with peripartum cardiomyopathy, the presence of TTN truncating variants was significantly correlated with a lower ejection fraction at 1-year follow-up (P = 0.005). CONCLUSIONS The distribution of truncating variants in a large series of women with peripartum cardiomyopathy was remarkably similar to that found in patients with idiopathic dilated cardiomyopathy. TTN truncating variants were the most prevalent genetic predisposition in each disorder.

Background Fatty acid amide hydrolase (FAAH) is a key enzyme in regulating endocannabinoid (eCB) signaling. A common single nucleotide polymorphism (C385A) in the human FAAH gene has been associated with increased risk for addiction and obesity. Methods Using imaging genetics in 82 healthy adult volunteers, we examined the effects of FAAH C385A on threat- and reward-related human brain function. Results Carriers of FAAH 385A, associated with reduced enzyme and, possibly, increased eCB signaling, had decreased threat-related amygdala reactivity but increased reward-related ventral striatal reactivity in comparison to C385 homozygotes. Similar divergent effects of FAAH C385A genotype were manifest at the level of brain-behavior relationships. 385A carriers showed decreased correlation between amygdala reactivity and trait anxiety but increased correlation between ventral striatal reactivity and delay discounting, an index of impulsivity. Conclusions Our results parallel pharmacologic and genetic dissection of eCB signaling, are consistent with the psychotropic effects of Δ9-tetrahydrocannabinol and highlight specific neural mechanisms through which variability in eCB signaling impacts complex behavioral processes related to risk for addiction and obesity.

BACKGROUND Peripartum cardiomyopathy (PPCM) remains a major cause of maternal morbidity and mortality. OBJECTIVES This study sought to prospectively evaluate recovery of the left ventricular ejection fraction (LVEF) and clinical outcomes in the multicenter IPAC (Investigations of Pregnancy Associated Cardiomyopathy) study. METHODS We enrolled and followed 100 women with PPCM through 1 year post-partum. The LVEF was assessed by echocardiography at baseline and at 2, 6, and 12 months post-partum. Survival free from major cardiovascular events (death, transplantation, or left ventricular [LV] assist device) was determined. Predictors of outcome, particularly race, parameters of LV dysfunction (LVEF), and remodeling (left ventricular end-diastolic diameter [LVEDD]) at presentation, were assessed by univariate and multivariate analyses. RESULTS The cohort was 30% black, 65% white, 5% other; the mean patient age was 30 ± 6 years; and 88% were receiving beta-blockers and 81% angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. The LVEF at study entry was 0.35 ± 0.10, 0.51 ± 0.11 at 6 months, and 0.53 ± 0.10 at 12 months. By 1 year, 13% had experienced major events or had persistent severe cardiomyopathy with an LVEF <0.35, and 72% achieved an LVEF ≥0.50. An initial LVEF <0.30 (p = 0.001), an LVEDD ≥6.0 cm (p < 0.001), black race (p = 0.001), and presentation after 6 weeks postpartum (p = 0.02) were associated with a lower LVEF at 12 months. No subjects with both a baseline LVEF <0.30 and an LVEDD ≥6.0 cm recovered by 1 year post-partum, whereas 91% with both a baseline LVEF ≥0.30 and an LVEDD <6.0 cm recovered (p < 0.00001). CONCLUSIONS In a prospective cohort with PPCM, most women recovered; however, 13% had major events or persistent severe cardiomyopathy. Black women had more LV dysfunction at presentation and at 6 and 12 months post-partum. Severe LV dysfunction and greater remodeling at study entry were associated with less recovery. (Investigations of Pregnancy Associated Cardiomyopathy [IPAC]; NCT01085955)

Autosomal ancestry informative markers (AIMs) are useful for inferring individual biogeographical ancestry (I-BGA) and admixture. Ancestry estimates obtained from Y and mtDNA are useful for reconstructing population expansions and migrations in our recent past but individual genomic admixture estimates are useful to test for association of admixture with phenotypes, as covariate in association studies to control for stratification and, in forensics, to estimate certain overt phenotypes from ancestry. We have developed a panel of 176 autosomal AIMs that can effectively distinguish I-BGA and admixture proportions from four continental ancestral populations: Europeans, West Africans, Indigenous Americans, and East Asians. We present allele frequencies for these AIMs in all four ancestral populations and use them to assess the global apportionment of I-BGA and admixture diversity among some extant populations. We observed patterns of apportionment similar to those described previously using sex and autosomal markers, such as European admixture for African Americans (14.3%) and Mexicans (43.2%), European (65.5%) and East Asian affiliation (27%) for South Asians, and low levels of African admixture (2.8-10.8%) mirroring the distribution of Y E3b haplogroups among various Eurasian populations. Using simulation studies and pedigree analysis we show that I-BGA estimates obtained using this panel and a four-population model has a high degree of precision (average root mean square error [RMSE]=0.026). Using ancestry-phenotype associations we demonstrate that a large and informative AIM panel such as this can help reduce false-positive and false-negative associations between phenotypes and admixture proportions, which may result when using a smaller panel of less informative AIMs.

The genetic basis of acute lung injury (ALI) is poorly understood. The myosin light chain kinase (MYLK) gene encodes the nonmuscle myosin light chain kinase isoform, a multifunctional protein involved in the inflammatory response (apoptosis, vascular permeability, leukocyte diapedesis). To examine MYLK as a novel candidate gene in sepsis-associated ALI, we sequenced exons, exon-intron boundaries, and 2 kb of 5 UTR of the MYLK, which revealed 51 single-nucleotide polymorphisms (SNPs). Potential association of 28 MYLK SNPs with sepsis-associated ALI were evaluated in a casecontrol sample of 288 European American subjects (EAs) with sepsis alone, subjects with sepsis-associated ALI, or healthy control subjects, and a sample population of 158 African American subjects (AAs) with sepsis and ALI. Significant single locus associations in EAs were observed between four MYLK SNPs and the sepsis phenotype (P Ͻ 0.001), with an additional SNP associated with the ALI phenotype (P ϭ 0.03). A significant association of a single SNP (identical to the SNP identified in EAs) was observed in AAs with sepsis (P ϭ 0.002) and with ALI (P ϭ 0.01). Three sepsis risk-conferring haplotypes in EAs were defined downstream of start codon of smooth muscle MYLK isoform, a region containing putative regulatory elements (P Ͻ 0.001). In contrast, multiple haplotypic analyses revealed an ALI-specific, risk-conferring haplotype at 5 of the MYLK gene in both European and African Americans and an additional 3 region haplotype only in African Americans. These data strongly implicate MYLK genetic variants to confer increased risk of sepsis and sepsis-associated ALI.Keywords: MYLK/MLCK; genetic association; SNP; ALI; sepsis Acute lung injury (ALI) is characterized by profound inflammation, increased vascular permeability, and alveolar flooding, a combination of events which frequently results in acute respiratory failure. The incidence of ALI in the United States (17-64 per 100,000 person-years) is higher than in other developed countries, with mortality rates for patients with acute respiratory distress syndrome, the more severe form of ALI, ranging from