Weiss, Scott T

Nononcogenic somatic mutations are thought to be uncommon and inconsequential. To test this, we analyzed 43,693 National Heart, Lung and Blood Institute Trans-Omics for Precision Medicine blood whole genomes from 37 cohorts and identified 7131 non-missense somatic mutations that are recurrently mutated in at least 50 individuals. These recurrent non-missense somatic mutations (RNMSMs) are not clearly explained by other clonal phenomena such as clonal hematopoiesis. RNMSM prevalence increased with age, with an average 50-year-old having 27 RNMSMs. Inherited germline variation associated with RNMSM acquisition. These variants were found in genes involved in adaptive immune function, proinflammatory cytokine production, and lymphoid lineage commitment. In addition, the presence of eight specific RNMSMs associated with blood cell traits at effect sizes comparable to Mendelian genetic mutations. Overall, we found that somatic mutations in blood are an unexpectedly common phenomenon with ancestry-specific determinants and human health consequences.

Human genetic studies support an inverse causal relationship between leukocyte telomere length (LTL) and coronary artery disease (CAD), but directionally mixed effects for LTL and diverse malignancies. Clonal hematopoiesis of indeterminate potential (CHIP), characterized by expansion of hematopoietic cells bearing leukemogenic mutations, predisposes both hematologic malignancy and CAD. TERT (which encodes telomerase reverse transcriptase) is the most significantly associated germline locus for CHIP in genome-wide association studies. Here, we investigated the relationship between CHIP, LTL, and CAD in the Trans-Omics for Precision Medicine (TOPMed) program ( n = 63,302) and UK Biobank ( n = 47,080). Bidirectional Mendelian randomization studies were consistent with longer genetically imputed LTL increasing propensity to develop CHIP, but CHIP then, in turn, hastens to shorten measured LTL (mLTL). We also demonstrated evidence of modest mediation between CHIP and CAD by mLTL. Our data promote an understanding of potential causal relationships across CHIP and LTL toward prevention of CAD.

Abstract Context Vitamin D (VD) deficiency in pregnancy and the neonatal period has impacts on childhood outcomes. Maternal VD sufficiency is crucial for sufficiency in the neonate, though the effect of early versus late pregnancy 25-hydroxy-vitamin D (25(OH)D) levels on neonatal levels is unknown. Furthermore, chemiluminescence immunoassays (CLIAs) are widely used, though their validity in measuring 25(OH)D specifically in cord blood specimens has not been established. Objective To assess the validity of a CLIA in the measurement of cord blood 25(OH)D and to evaluate maternal determinants of neonatal 25(OH)D, including early versus late pregnancy 25(OH)D levels. Design This is an ancillary analysis from the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized, double-blinded, placebo-controlled study. Participants and Intervention A total of 881 pregnant women at high risk of having offspring asthma were randomized to receive VD supplementation or placebo. Serum samples were collected from mothers in early and late pregnancy and from offspring cord blood at birth. 25(OH)D levels were assayed by CLIA in all maternal and offspring samples and by LC-MS/MS in all offspring samples and a subset of 200 maternal third trimester samples. Results Cord blood 25(OH)D levels were higher as measured by CLIA (mean 37.13 ng/mL [SD 18.30]) than by LC-MS/MS (mean 23.54 ng/mL [SD 11.99]), with a mean positive bias of 13.54 ng/mL (SD 12.92) by Bland-Altman analysis. This positive bias in measurement by CLIA was not observed in maternal samples. Third trimester 25(OH)D was a positive determinant of neonatal 25(OH)D levels. Conclusion Chemiluminescence immunoassays overestimate 25(OH)D levels in human cord blood samples, an effect not observed in maternal blood samples. The quantification of 25(OH)D by CLIA should therefore not be considered valid when assayed in cord blood samples. Third trimester, but not first trimester, maternal 25(OH)D is one of several determinants of neonatal 25(OH)D status.