Juha Karjalainen

Female infertility is a common and complex health problem affecting millions of women worldwide. While multiple factors can contribute to this condition, the underlying cause remains elusive in up to 15-30% of cases. In our large genome-wide association study (GWAS) of 22,849 women with infertility and 198,989 controls from the Finnish population cohort FinnGen, we unveil a unique landscape of genetic factors associated with the disease. Our recessive analysis identified a low-frequency stop-gained mutation in TBPL2 (p.Arg331Ter; minor allele frequency (MAF) = 1.2%) with an impact comparable to highly penetrant monogenic mutations (OR = 650, p = 4.1 ×10 ^-25 ). While previous studies have linked the homologous gene to anovulation and sterility in knockout mice, the severe consequence of the p.Arg331Ter mutation was evidenced by homozygous carriers having significantly fewer offspring (average of 0.16) compared to women belonging to the other genotype groups (average of 1.75 offspring, p = 1.4×10 ^-15 ). Notably, all homozygous women who had given birth had received infertility therapy. Moreover, our age-stratified analyses identified three additional genome-wide significant loci. Two loci were associated with early-onset disease (infertility diagnosed before age 30), located near CHEK2 and within the major histocompatibility complex (MHC)-region. The third locus, associated with late-onset disease, had its lead SNP located in an intron of a lncRNA gene. Taken together, our data highlight the significance of rare recessive alleles in shaping female infertility risk. The results further provide evidence supporting specific age-dependent mechanisms underlying this complex disorder.

There is currently only limited understanding of the genetic aetiology of obstructive sleep apnoea (OSA). The aim of our study is to identify genetic loci associated with OSA risk and to test if OSA and its comorbidities share a common genetic background. We conducted the first large-scale genome-wide association study of OSA using FinnGen Study (217,955 individuals) with 16,761 OSA patients identified using nationwide health registries. We estimated 8.3% [0.06-0.11] heritability and identified five loci associated with OSA (P < 5.0 × 10 ⁻⁸ ): rs4837016 near GTPase activating protein and VPS9 domains 1 ( GAPVD1 ), rs10928560 near C-X-C motif chemokine receptor 4 ( CXCR4 ), rs185932673 near Calcium/calmodulin-dependent protein kinase ID ( CAMK1D ) and rs9937053 near Fat mass and obesity-associated protein ( FTO ) - a variant previously associated with body mass index (BMI). In a BMI-adjusted analysis, an association was observed for rs10507084 near Rhabdomyosarcoma 2 associated transcript ( RMST )/NEDD1 gamma-tubulin ring complex targeting factor ( NEDD1 ). We found genetic correlations between OSA and BMI (rg=0.72 [0.62-0.83]) and with comorbidities including hypertension, type 2 diabetes (T2D), coronary heart disease (CHD), stroke, depression, hypothyroidism, asthma and inflammatory rheumatic diseases (IRD) (rg > 0.30). Polygenic risk score (PRS) for BMI showed 1.98-fold increased OSA risk between the highest and the lowest quintile and Mendelian randomization supported a causal relationship between BMI and OSA. Our findings support the causal link between obesity and OSA and joint genetic basis between OSA and comorbidities.

Protein-altering variants that are protective against human disease provide in vivo validation of therapeutic targets. Here we use genotyping data in UK Biobank and FinnGen to conduct a search for protein-altering variants conferring lower intraocular pressure (IOP) and protection against glaucoma. Through protein-altering variant association analysis we find a missense variant in UK Biobank (rs28991009 (MAF=0.8%) genotyped in 81,527 individuals with measured IOP and an independent set of 4,269 glaucoma patients and 251,355 controls) that significantly lowers IOP (β = −0.73 mmHg for heterozygotes, −2.96 mmHg for homozygotes, P = 1 × 10 ⁻¹³ ) and is associated with 34% reduced risk of glaucoma ( P = 0.005). In FinnGen, we identify an ANGPTL7 missense variant at a greater than 50-fold increased frequency in Finland compared with other populations (rs147660927, p.Arg220Cys, MAF Finland = 4.1%), which was genotyped in 5,177 glaucoma patients and 130,461 controls and is associated with 30% lower glaucoma risk ( P = 1 × 10 ⁻⁹ ). We further find three rarer variants in UK Biobank, including a protein-truncating variant, which confer a strong composite lowering of IOP ( P = 0.002), suggesting the protective mechanism likely resides in the loss of an interaction or function. Our results support inhibition or down-regulation of ANGPTL7 as a therapeutic strategy for glaucoma

Aim: Genetic investigation of human plasma lipidome to get insights into lipid-related disorders beyond traditional lipid measures. Methods and Results: We performed a genome-wide association study (GWAS) of 141 lipid species (n=2,181 individuals), followed by phenome-wide scans (PheWAS) with 44 clinical endpoints related to cardiometabolic, psychiatric and gastrointestinal disorders (n=456,941 individuals). SNP-based heritability for lipid species ranged from 0.10-0.54. Lipids with long-chain polyunsaturated fatty acids showed higher heritability and genetic sharing, suggesting considerable genetic regulation at acyl chains levels. We identified 35 genomic regions associated with at least one lipid species (P−8 ), revealing 37 new SNP-lipid species pair associations e.g. new association between ABCG5/8 and CE(20:2;0). PheWAS of lipid-species-associated loci suggested new associations of BLK with obesity, FADS2 with thrombophlebitis, and BLK and SPTLC3 with gallbladder disease (false discovery rate SYNGR1, MIR100HG , and PTPRN2 in desaturation and/or elongation of fatty acids. At known lipid loci ( FADS2, APOA5 and LPL ), genetic associations provided detailed insights to their roles in lipid biology and diseases. We also show that traditional lipid measures may fail to capture lipids such as lysophospatidylcholines (LPCs) and phosphatidylcholines (PCs) that are potential disease risk factors, but are not included in routine screens. The full genome-wide association statistics are available on the web-based database ( http://35.205.141.92 ). Conclusion: Our study reveals genetic regulation of plasma lipidome and highlights the potential of lipidomic profiling in disease gene mapping.