Miscarriage risk assessment: a bioinformatic approach to identifying candidate lethal genes and variants.

PURPOSE: Miscarriage, often resulting from a variety of genetic factors, is a common pregnancy outcome. Preconception genetic carrier screening (PGCS) identifies at-risk partners for newborn genetic disorders; however, PGCS panels currently lack miscarriage-related genes. In this study, we evaluated the potential impact of both known and candidate genes on prenatal lethality and the effectiveness of PGCS in diverse populations. METHODS: We analyzed 125,748 human exome sequences and mouse and human gene function databases. Our goals were to identify genes crucial for human fetal survival (lethal genes), to find variants not present in a homozygous state in healthy humans, and to estimate carrier rates of known and candidate lethal genes in various populations and ethnic groups. RESULTS: This study identified 138 genes in which heterozygous lethal variants are present in the general population with a frequency of 0.5% or greater. Screening for these 138 genes could identify 4.6% (in the Finnish population) to 39.8% (in the East Asian population) of couples at risk of miscarriage. This explains the cause of pregnancy loss in approximately 1.1-10% of cases affected by biallelic lethal variants. CONCLUSION: This study has identified a set of genes and variants potentially associated with lethality across different ethnic backgrounds. The variation of these genes across ethnic groups underscores the need for a comprehensive, pan-ethnic PGCS panel that includes genes related to miscarriage.

Preconception Genetic Carrier Screening for Miscarriage Risk Assessment: A Bioinformatic Approach to Identifying Candidate Lethal Genes and Variants.

Purpose: Miscarriage, due to genetically heterogeneous etiology, is a common outcome of pregnancy. Preconception genetic carrier screening (PGCS) identifies at-risk partners for newborn genetic disorders; however, PGCS panels currently lack miscarriage-related genes. Here we assessed the theoretical impact of known and candidate genes on prenatal lethality and the PGCS among diverse populations. Methods: Human exome sequencing and mouse gene function databases were analyzed to define genes essential for human fetal survival (lethal genes), identify variants that are absent in a homozygous state in healthy human population, and to estimate carrier rates for known and candidate lethal genes. Results: Among 138 genes, potential lethal variants are present in the general population with a frequency of 0.5% or greater. Preconception screening for these 138 genes would identify from 4.6% (Finnish population) to 39.8% (East Asian population) of couples that are at-risk for miscarriage, explaining a cause for pregnancy loss for ∼1.1-10% of conceptions affected by biallelic lethal variants. Conclusion: This study identified a set of genes and variants potentially associated with lethality across different ethnic backgrounds. The diversity of these genes amongst the various ethnic groups highlights the importance of designing a pan-ethnic PGCS panel comprising miscarriage-related genes.

Sohlh1 loss of function male and female infertility model impacts overall health beyond gonadal dysfunction in mice†.

Reproductive longevity is associated with health outcomes. Early menopause, loss of ovarian function, and male infertility are linked to shorter lifespan and increased adverse health outcomes. Here we examined the extragonadal effects of whole animal loss of spermatogenesis and oogenesis specific basic helix-loop-helix 1 (Sohlh1) gene in mice, a well-described mouse model of female and male infertility. Sohlh1 encodes a transcription factor that is primarily expressed in the male and female germline and regulates germline differentiation. The Sohlh1 knockout mouse model, just like human individuals with SOHLH1 loss of function, presents with hypergonadotropic hypogonadism and loss of ovarian function in females and impaired spermatogenesis in males, with a seemingly gonad restricted phenotype in both sexes. However, extragonadal phenotyping revealed that Sohlh1 deficiency leads to abnormal immune profiles in the blood and ovarian tissues of female animals, sex-specific alterations of metabolites, and behavior and cognition changes. Altogether, these results show that Sohlh1 deficiency impacts overall health in both male and female mice.