Self-reported history of iron-deficiency anemia was associated with self-reported history of depression. Furthermore, self-reported history of iron-deficiency anemia was associated with higher psychological distress.

No abstract

Major depressive disorder (MDD) is a common and disabling psychiatric disorder. A recent mega analysis of genome-wide association studies (GWASs) identified 44 loci associated with MDD, though most of the genetic etiologies of the MDD/psychological distress remain unclear. To further understand the genetic basis of MDD/psychological distress, we conducted a GWAS in East Asia with more than 10,000 participants of Japanese ancestry who had enrolled in a direct-to-consumer genetic test. After quality control on the genotype data, 10,330 subjects with a total of 8,567,708 imputed SNPs were eligible for the analysis. The participants completed a self-administered questionnaire on their past medical history and health conditions that included the 6-item Kessler screening scale (K6 scale) for psychological distress (cut-off point of 5) and past medical history of MDD, resulting in 3981 subjects assigned to “psychologically distressed group” [cases], and the remaining 6349 subjects were assigned to the “non-psychologically distressed group” [controls]. In this GWAS, we found an association with genome-wide significance at rs6073833 (P = 7.60 × 10−9) in 20q13.12. This is, to the best of our knowledge, the first large-scale GWAS for psychological distress using data from direct-to-consumer (DTC) genetic tests in a population of non-European-ancestry, and the present study thus detected a novel locus significantly associated with psychological distress in the Japanese population.

Photic sneeze syndrome (PSS) is characterized by a tendency to sneeze when the eye is exposed to bright light. Recent genome-wide association studies (GWASs) have identified single-nucleotide polymorphisms (SNPs) associated with PSS in Caucasian populations. We performed a GWAS on PSS in Japanese individuals who responded to a web-based survey and provided saliva samples. After quality control, genotype data of 210,086 SNPs in 11,409 individuals were analyzed. The overall prevalence of PSS was 3.2%. Consistent with previous reports, SNPs at 3p12.1 were associated with PSS at genome-wide significance (p < 5.0 × 10). Furthermore, two novel loci at 9q34.2 and 4q35.2 reached suggestive significance (p < 5.0 × 10). Our data also provided evidence supporting the two additional SNPs on 2q22.3 and 9q33.2 reportedly associated with PSS. Our study reproduced previous findings in Caucasian populations and further suggested novel PSS loci in the Japanese population.

Carbonaceous chondrites contain life’s essential building blocks, including amino acids, and their delivery of organic compounds would have played a key role in life’s emergence on Earth. Aqueous alteration of carbonaceous chondrites is a widespread process induced by the heat produced by radioactive decay of nuclides like 26Al. Simple ubiquitous molecules like formaldehyde and ammonia could produce various organic compounds, including amino acids and complex organic macromolecules. However, the effects of radiation on such organic chemistry are unknown. Hence, the effects of gamma rays from radioactive decays on the formation of amino acids in meteorite parent bodies are demonstrated here. We discovered that gamma-ray irradiation of aqueous formaldehyde and ammonia solutions afforded a variety of amino acids. The amino acid yields had a linear relationship with the total gamma-ray dose but were unaffected by the irradiation dose rates. Given the gamma-ray production rates in the meteorite parent bodies, we estimated that the production rates were reasonable compared to amino acid abundances in carbonaceous chondrites. Our findings indicate that gamma rays may contribute to amino acid formation in parent bodies during aqueous alteration. In this paper, we propose a new prebiotic amino acid formation pathway that contributes to life’s origin.