Predicting Heterogeneity in Patient Response to Morphine Treatment for Neonatal Opioid Withdrawal Syndrome

Infants with neonatal opioid withdrawal syndrome commonly receive morphine treatment to manage their withdrawal signs. However, the effectiveness of this pharmacotherapy in managing the infants' withdrawal signs vary widely. We sought to understand how information available early in infant monitoring can anticipate this treatment response, focusing on early modified Finnegan Neonatal Abstinence Scoring System (FNASS) scores, polygenic risk for opioid dependence (polygenic risk score (PRS)), and drug exposure. Using k-means clustering, we divided the 213 infants in our cohort into 3 groups based on their FNASS scores in the 12 hours before and after the initiation of pharmacotherapy. We found that these groups were pairwise significantly different for risk factors, including methadone exposure, and for in-hospital outcomes, including total morphine received, length of stay, and highest FNASS score. Whereas PRS was not predictive of receipt of treatment, PRS was pairwise significantly different between a subset of the groups. Using tree-based machine learning methods, we then constructed network graphs of the relationships among these groups, FNASS scores, PRS, drug exposures, and in-hospital outcomes. The resulting networks also showed meaningful connection between early FNASS scores and PRS, as well as between both of those and later in-hospital outcomes. These analyses present clinicians with the opportunity to better anticipate infant withdrawal progression and prepare accordingly, whether with expedited morphine treatment or non-pharmacotherapeutic alternative treatments.

KCNQ1 and Long QT Syndrome in 1/45 Amish: The Road From Identification to Implementation of Culturally Appropriate Precision Medicine

Supplemental Digital Content is available in the text.

In population-based research exome sequencing, the path from variant discovery to return of results is not well established. Variants discovered by research exome sequencing have the potential to improve population health.

Abstract 100: Sorting Nexin 1: Molecular Mechanisms and Pharmacogenomics

Sorting nexin 1 (SNX1) plays a pivotal role for the normal activity of renal dopamine D5 receptor (D5R). Kidney-restricted, Snx1-siRNA depletion of SNX1 results in impaired natriuretic response to salt load and hypertension in mice. Genetic ablation of the Snx1 gene (Snx1-/-) resulted in increased oxidative stress, impaired sodium excretion, and elevated systolic blood pressure (SBP, 131.3±6.4 mm Hg, n=5) in mice. The D5R has antioxidant properties by negatively regulating the expression of the NADPH oxidase (NOX). We found that NOX1, NOX2, and p47phox, as well as the antioxidant PON2, conceivably as compensation, were increased in Snx1-/- mice compared with wild-type littermates. Snx1-/- mice had higher ROS (218.6±7.7%), NOX activity (43.9±3.3 AU/mg protein/min vs. 25.98±3.5), and other markers of oxidative stress, e.g., malonyldialdehyde (32.5±3.4 pmol/mg protein vs. 17.2±2.1) and 3-nitrotyrosine (128.3±4%), which were all normalized by 10-day renal infusion of apocynin, a drug that prevents NOX assembly. The SBP in Snx1-/- mice was also normalized by apocynin (131.3±4.8 mm Hg to 105.7±0.3). Compared with human renal proximal tubule cells obtained from normotensive Caucasian males (NT cells), those from hypertensive subjects (HT cells) had reduced expression of SNX1 (160±2.1%, n=4=5/group), increased ROS (182±10.5%), and blunted cAMP response (110.8±35.3%) and sodium transport inhibition (101.2±1.9%) in response to D1-like receptor stimulation. These observations were corroborated by results in siRNA-induced gene silencing in NT cells or “genetic rescue” in HT cells. We also evaluated 12 SNPs in the SNX1 gene as possible genetic predictors of BP response to monotherapy with HCTZ among hypertensive patients enrolled in the Pharmacogenomic Evaluation of Antihypertensive Responses study (n=768). Three of the 12 SNPs (rs12591947, rs11854249, and rs11635627) associated with poor BP response to thiazide ([[Unable to Display Character: ∆]] SBP of -1.8 mm Hg vs. 113.5) among blacks. An SNX1 SNP (rs1802376) was associated with essential hypertension in a Caucasian population (n=502). Our data demonstrate the novelty and relevance of SNX1 in human pathology and pharmacogenomics of essential hypertension.

Gene-centric meta-analyses for central adiposity traits in up to 57 412 individuals of European descent confirm known loci and reveal several novel associations

Waist circumference (WC) and waist-to-hip ratio (WHR) are surrogate measures of central adiposity that are associated with adverse cardiovascular events, type 2 diabetes and cancer independent of body mass index (BMI). WC and WHR are highly heritable with multiple susceptibility loci identified to date. We assessed the association between SNPs and BMI-adjusted WC and WHR and unadjusted WC in up to 57 412 individuals of European descent from 22 cohorts collaborating with the NHLBI's Candidate Gene Association Resource (CARe) project. The study population consisted of women and men aged 20-80 years. Study participants were genotyped using the ITMAT/Broad/CARE array, which includes ∼50 000 cosmopolitan tagged SNPs across ∼2100 cardiovascular-related genes. Each trait was modeled as a function of age, study site and principal components to control for population stratification, and we conducted a fixed-effects meta-analysis. No new loci for WC were observed. For WHR analyses, three novel loci were significantly associated (P < 2.4 × 10(-6)). Previously unreported rs2811337-G near TMCC1 was associated with increased WHR (β ± SE, 0.048 ± 0.008, P = 7.7 × 10(-9)) as was rs7302703-G in HOXC10 (β = 0.044 ± 0.008, P = 2.9 × 10(-7)) and rs936108-C in PEMT (β = 0.035 ± 0.007, P = 1.9 × 10(-6)). Sex-stratified analyses revealed two additional novel signals among females only, rs12076073-A in SHC1 (β = 0.10 ± 0.02, P = 1.9 × 10(-6)) and rs1037575-A in ATBDB4 (β = 0.046 ± 0.01, P = 2.2 × 10(-6)), supporting an already established sexual dimorphism of central adiposity-related genetic variants. Functional analysis using ENCODE and eQTL databases revealed that several of these loci are in regulatory regions or regions with differential expression in adipose tissue.