Browsing by Subject "LINKAGE"

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  • Bhutta, Mahmood F.; Lambie, Jane; Hobson, Lindsey; Goel, Anuj; Hafren, Lena; Einarsdottir, Elisabet; Mattila, Petri S.; Farrall, Martin; Brown, Steve; Burton, Martin J. (2017)
    Chronic otitis media with effusion (COME) is the most common cause of hearing loss in children, and known to have high heritability. Mutant mouse models have identified Fbxo11, Evi1, Tgif1, and Nisch as potential risk loci. We recruited children aged 10 and under undergoing surgical treatment for COME from 35 hospitals in the UK, and their nuclear family. We performed association testing with the loci FBXO11, EVI1, TGIF1 and NISCH and sought to replicate significant results in a case-control cohort from Finland. We tested 1296 families (3828 individuals), and found strength of association with the T allele at rs881835 (p = 0.006, OR 1.39) and the G allele at rs1962914 (p = 0.007, OR 1.58) at TGIF1, and the A allele at rs10490302 (p = 0.016, OR 1.17) and the G allele at rs2537742 (p = 0.038, OR 1.16) at FBXO11. Results were not replicated. This study supports smaller studies that have also suggested association of otitis media with polymorphism at FBX011, but this is the first study to report association with the locus TGIF1. Both FBX011 and TGIF1 are involved in TGF-beta signalling, suggesting this pathway may be important in the transition from acute to chronic middle ear inflammation, and a potential molecular target.
  • Koskinen, Lotta L. E.; Seppala, Eija H.; Weissl, Jutta; Jokinen, Tarja S.; Viitmaa, Ranno; Hanninen, Reetta L.; Quignon, Pascale; Fischer, Andrea; Andre, Catherine; Lohi, Hannes (2017)
    Background: Idiopathic or genetic adult-onset epilepsy is a common neurological disorder in domestic dogs. Genetic association has been reported only with ADAM23 on CFA 37 in few breeds. To identify novel epilepsy genes, we performed genome-wide association (GWA) analyses in four new breeds, and investigated the association of the previously reported ADAM23 haplotype with the epilepsy phenotype in eight breeds. Results: GWA analysis did not reveal new epilepsy loci. ADAM23 association (p <0.05) was identified in five breeds. Combined analysis of all eight breeds showed significant association (p = 4.6e(-6), OR 1.9). Conclusions: Our results further support the role of ADAM23 in multiple breeds as a common risk gene for epilepsy with low penetrance. The lack of findings in the GWA analyses points towards inefficient capture of genetic variation by the current SNP arrays, causal variant(s) with low penetrance and possible phenocopies. Future work will include studies on ADAM23 function and expression in canine neurons, as well as whole-genome sequencing in order to identify additional IE genes.
  • Within-family Consortium; 23andMe Res Team; Brumpton, Ben; Sanderson, Eleanor; Heilbron, Karl; Kaprio, Jaakko; Davies, Neil M. (2020)
    Estimates from Mendelian randomization studies of unrelated individuals can be biased due to uncontrolled confounding from familial effects. Here we describe methods for within-family Mendelian randomization analyses and use simulation studies to show that family-based analyses can reduce such biases. We illustrate empirically how familial effects can affect estimates using data from 61,008 siblings from the Nord-TrOndelag Health Study and UK Biobank and replicated our findings using 222,368 siblings from 23andMe. Both Mendelian randomization estimates using unrelated individuals and within family methods reproduced established effects of lower BMI reducing risk of diabetes and high blood pressure. However, while Mendelian randomization estimates from samples of unrelated individuals suggested that taller height and lower BMI increase educational attainment, these effects were strongly attenuated in within-family Mendelian randomization analyses. Our findings indicate the necessity of controlling for population structure and familial effects in Mendelian randomization studies. Family-based study designs have been applied to resolve confounding by population stratification, dynastic effects and assortative mating in genetic association analyses. Here, Brumpton et al. describe theory and simulations for overcoming such biases in Mendelian randomization through within-family studies.
  • FinnDiane Study; Vuori, Nadja; Sandholm, Niina; Kumar, Anmol; Hietala, Kustaa; Syreeni, Anna; Forsblom, Carol; Juuti-Uusitalo, Kati; Skottman, Heli; Imamura, Minako; Maeda, Shiro; Summanen, Paula A.; Lehto, Markku; Groop, Per-Henrik (2019)
    Diabetic retinopathy is a common diabetes complication that threatens the eyesight and may eventually lead to acquired visual impairment or blindness. While a substantial heritability has been reported for proliferative diabetic retinopathy (PDR), only a few genetic risk factors have been identified. Using genome-wide sib pair linkage analysis including 361 individuals with type 1 diabetes, we found suggestive evidence of linkage with PDR at chromosome 10p12 overlapping the CACNB2 gene (logarithm of odds = 2.73). Evidence of association between variants in CACNB2 and PDR was also found in association analysis of 4,005 individuals with type 1 diabetes with an odds ratio of 0.83 and P value of 8.6 x 10(-4) for rs11014284. Sequencing of CACNB2 revealed two coding variants, R476C/rs202152674 and S502L/rs137886839. CACNB2 is abundantly expressed in retinal cells and encodes the beta 2 subunit of the L-type calcium channel. Blocking vascular endothelial growth factor (VEGF) by intravitreous anti-VEGF injections is a promising clinical therapy to treat PDR. Our data show that L-type calcium channels regulate VEGF expression and secretion from retinal pigment epithelial cells (ARPE19) and support the role of CACNB2 via regulation of VEGF in the pathogenesis of PDR. However, further genetic and functional studies are necessary to consolidate the findings.
  • Chan, Yingleong; Holmen, Oddgeir L.; Dauber, Andrew; Vatten, Lars; Havulinna, Aki S.; Skorpen, Frank; Kvaloy, Kirsti; Silander, Kaisa; Nguyen, Thutrang T.; Willer, Cristen; Boehnke, Michael; Perola, Markus; Palotie, Aarno; Salomaa, Veikko; Hveem, Kristian; Frayling, Timothy M.; Hirschhorn, Joel N.; Weedon, Michael N. (2011)
  • Nene, Nuno R.; Mustonen, Ville; Illingworth, Christopher J. R. (2018)
    The Wright-Fisher model is the most popular population model for describing the behaviour of evolutionary systems with a finite population size. Approximations have commonly been used but the model itself has rarely been tested against time-resolved genomic data. Here, we evaluate the extent to which it can be inferred as the correct model under a likelihood framework. Given genome-wide data from an evolutionary experiment, we validate the Wright-Fisher drift model as the better option for describing evolutionary trajectories in a finite population. This was found by evaluating its performance against a Gaussian model of allele frequency propagation. However, we note a range of circumstances under which standard Wright-Fisher drift cannot be correctly identified. (C) 2017 The Author(s). Published by Elsevier Ltd.
  • Salmela, Elina; Renvall, Hanna; Kujala, Jan; Hakosalo, Osmo; Illman, Mia; Vihla, Minna; Leinonen, Eira; Salmelin, Riitta; Kere, Juha (2016)
    Several functional and morphological brain measures are partly under genetic control. The identification of direct links between neuroimaging signals and corresponding genetic factors can reveal cellular-level mechanisms behind the measured macroscopic signals and contribute to the use of imaging signals as probes of genetic function. To uncover possible genetic determinants of the most prominent brain signal oscillation, the parieto-occipital 10-Hz alpha rhythm, we measured spontaneous brain activity with magnetoencephalography in 210 healthy siblings while the subjects were resting, with eyes closed and open. The reactivity of the alpha rhythm was quantified from the difference spectra between the two conditions. We focused on three measures: peak frequency, peak amplitude and the width of the main spectral peak. In accordance with earlier electroencephalography studies, spectral peak amplitude was highly heritable (h(2)>0.75). Variance component-based analysis of 28000 single-nucleotide polymorphism markers revealed linkage for both the width and the amplitude of the spectral peak. The strongest linkage was detected for the width of the spectral peak over the left parieto-occipital cortex on chromosome 10 (LOD=2.814, nominal P
  • Prasad, Rashmi B.; Lessmark, Anna; Almgren, Peter; Kovacs, Gyorgyi; Hansson, Ola; Oskolkov, Nikolay; Vitai, Marta; Ladenvall, Claes; Kovacs, Peter; Fadista, Joao; Lachmann, Michael; Zhou, Yuedan; Sonestedt, Emily; Poon, Wenny; Wollheim, Claes B.; Orho-Melander, Marju; Stumvoll, Michael; Tuomi, Tiinamaija; Paeaebo, Svante; Koranyi, Laszlo; Groop, Leif (2016)
    Aims/hypothesis Genome-wide association studies (GWAS) have identified more than 65 genetic loci associated with risk of type 2 diabetes. However, the contribution of distorted parental transmission of alleles to risk of type 2 diabetes has been mostly unexplored. Our goal was therefore to search for parent-of-origin effects (POE) among type 2 diabetes loci in families. Methods Families from the Botnia study (n = 4,211, 1,083 families) were genotyped for 72 single-nucleotide polymorphisms (SNPs) associated with type 2 diabetes and assessed for POE on type 2 diabetes. The family-based Hungarian Transdanubian Biobank (HTB) (n = 1,463, > 135 families) was used to replicate SNPs showing POE. Association of type 2 diabetes loci within families was also tested. Results Three loci showed nominal POE, including the previously reported variants in KCNQ1, for type 2 diabetes in families from Botnia (rs2237895: p(POE) = 0.037), which can be considered positive controls. The strongest POE was seen for rs7578597 SNP in the THADA gene, showing excess transmission of the maternal risk allele T to diabetic offspring (Botnia: p(POE) = 0.01; HTB p(POE) = 0.045). These data are consistent with previous evidence of allelic imbalance for expression in islets, suggesting that the THADA gene can be imprinted in a POE-specific fashion. Five CpG sites, including those flanking rs7578597, showed differential methylation between diabetic and non-diabetic donor islets. Conclusions/interpretation Taken together, the data emphasise the need for genetic studies to consider from which parent an offspring has inherited a susceptibility allele.
  • Kaartokallio, Tea; Wang, Jingwen; Heinonen, Seppo Tapani; Kajantie, Eero; Kivinen, Katja; Pouta, Anneli; Gerdhem, Paul; Jiao, Hong; Kere, Juha; Laivuori, Hannele (2016)
    Pre-eclampsia is a common pregnancy disorder that is a major cause for maternal and perinatal mortality and morbidity. Variants predisposing to pre-eclampsia might be under negative evolutionary selection that is likely to keep their population frequencies low. We exome sequenced samples from a hundred Finnish pre-eclamptic women in pools of ten to screen for low-frequency, large-effect risk variants for pre-eclampsia. After filtering and additional genotyping steps, we selected 28 low-frequency missense, nonsense and splice site variants that were enriched in the pre-eclampsia pools compared to reference data, and genotyped the variants in 1353 pre-eclamptic and 699 non-pre-eclamptic women to test the association of them with pre-eclampsia and quantitative traits relevant for the disease. Genotypes from the SISu project (n = 6118 exome sequenced Finnish samples) were included in the binary trait association analysis as a population reference to increase statistical power. In these analyses, none of the variants tested reached genome-wide significance. In conclusion, the genetic risk for pre-eclampsia is likely complex even in a population isolate like Finland, and larger sample sizes will be necessary to detect risk variants.
  • Jacobsen, Kaya K.; Nievergelt, Caroline M.; Zayats, Tetyana; Greenwood, Tiffany A.; Anttila, Verneri; Akiskal, Hagop S.; Haavik, Jan; Fasmer, Ole Bernt; Kelsoe, John R.; Johansson, Stefan; Oedegaard, Ketil J.; BiGs Consortium IHG Consortium; Liu, Chengyu; Wedenoja, Juho Olavi; Kaunisto, Mari Anneli; Heikkilä, Kauko Veli; Kaprio, Jaakko Arthur; Wessman, Maija; Kallela, Mikko; Färkkilä, Markus; Artto, Ville; Eriksson, Johan; Palotie, Aarno Veikko; Daly, Mark (2015)
  • Einarsdottir, Elisabet; Hafren, Lena; Leinonen, Eira; Bhutta, Mahmood F.; Kentala, Erna; Kere, Juha; Mattila, Petri S. (2016)
    To identify genetic risk factors of childhood otitis media (OM), a genome-wide association study was performed on Finnish subjects, 829 affected children, and 2118 randomly selected controls. The most significant and validated finding was an association with an 80 kb region on chromosome 19. It includes the variants rs16974263 (P = 1.77 x 10(-7), OR = 1.59), rs268662 (P = 1.564 x 10(-6), OR = 1.54), and rs4150992 (P = 3.37 x 10(-6), OR = 1.52), and harbors the genes PLD3, SERTAD1, SERTAD3, HIPK4, PRX, and BLVRB, all in strong linkage disequilibrium. In a sub-phenotype analysis of the 512 patients with chronic otitis media with effusion, one marker reached genome-wide significance (rs16974263, P = 2.92 x 10(-8)). The association to this locus was confirmed but with an association signal in the opposite direction, in a UK family cohort of 4860 subjects (rs16974263, P = 3.21 x 10(-4), OR = 0.72; rs4150992, P = 1.62 x 10(-4), OR = 0.71). Thus we hypothesize that this region is important for COME risk in both the Finnish and UK populations, although the precise risk variants or haplotype background remain unclear. Our study suggests that the identified region on chromosome 19 includes a novel and previously uncharacterized risk locus for OM.
  • Hällfors, Jenni; Palviainen, Teemu; Surakka, Ida; Gupta, Richa; Buchwald, Jadwiga; Raevuori, Anu; Ripatti, Samuli; Korhonen, Tellervo; Jousilahti, Pekka; Madden, Pamela A. F.; Kaprio, Jaakko; Loukola, Anu (2019)
    The heritability of nicotine dependence based on family studies is substantial. Nevertheless, knowledge of the underlying genetic architecture remains meager. Our aim was to identify novel genetic variants responsible for interindividual differences in smoking behavior. We performed a genome-wide association study on 1715 ever smokers ascertained from the population-based Finnish Twin Cohort enriched for heavy smoking. Data imputation used the 1000 Genomes Phase I reference panel together with a whole genome sequence-based Finnish reference panel. We analyzed three measures of nicotine addiction-smoking quantity, nicotine dependence and nicotine withdrawal. We annotated all genome-wide significant SNPs for their functional potential. First, we detected genome-wide significant association on 16p12 with smoking quantity (P = 8.5 x 10(-9)), near CLEC19A. The lead-SNP stands 22 kb from a binding site for NF-kappa B transcription factors, which play a role in the neurotrophin signaling pathway. However, the signal was not replicated in an independent Finnish population-based sample, FINRISK (n = 6763). Second, nicotine withdrawal showed association on 2q21 in an intron of TMEM163 (P = 2.1 x 10(-9)), and on 11p15 (P = 6.6 x 10(-8)) in an intron of AP2A2, and P = 4.2 x 10(-7) for a missense variant in MUC6, both involved in the neurotrophin signaling pathway). Third, association was detected on 3p22.3 for maximum number of cigarettes smoked per day (P = 3.1 x 10(-8)) near STAC. Associating CLEC19A and TMEM163 SNPs were annotated to influence gene expression or methylation. The neurotrophin signaling pathway has previously been associated with smoking behavior. Our findings further support the role in nicotine addiction.
  • Kiryluk, Krzysztof; Li, Yifu; Sanna-Cherchi, Simone; Rohanizadegan, Mersedeh; Suzuki, Hitoshi; Eitner, Frank; Snyder, Holly J.; Choi, Murim; Hou, Ping; Scolari, Francesco; Izzi, Claudia; Gigante, Maddalena; Gesualdo, Loreto; Savoldi, Silvana; Amoroso, Antonio; Cusi, Daniele; Zamboli, Pasquale; Julian, Bruce A.; Novak, Jan; Wyatt, Robert J.; Mucha, Krzysztof; Perola, Markus; Kristiansson, Kati; Viktorin, Alexander; Magnusson, Patrik K.; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Stefansson, Kari; Boland, Anne; Metzger, Marie; Thibaudin, Lise; Wanner, Christoph; Jager, Kitty J.; Goto, Shin; Maixnerova, Dita; Karnib, Hussein H.; Nagy, Judit; Panzer, Ulf; Xie, Jingyuan; Chen, Nan; Tesar, Vladimir; Narita, Ichiei; Berthoux, Francois; Floege, Juergen; Stengel, Benedicte; Zhang, Hong; Lifton, Richard P.; Gharavi, Ali G. (2012)
  • FINNAKI Study Grp; Vilander, Laura M.; Vaara, Suvi T.; Donner, Kati M.; Lakkisto, Päivi; Kaunisto, Mari A.; Pettilä, Ville (2019)
    Acute kidney injury (AKI) is a syndrome that frequently affects the critically ill. Recently, an increased number of dinucleotide repeats in the HMOX1 gene were reported to associate with development of AKI in cardiac surgery. We aimed to test the replicability of this finding in a Finnish cohort of critically ill septic patients. This multicenter study was part of the national FINNAKI study. We genotyped 300 patients with severe AKI (KDIGO 2 or 3) and 353 controls without AKI (KDIGO 0) for the guanine-thymine (GTn) repeat in the promoter region of the HMOX1 gene. The allele calling was based on the number of repeats, the cut off being 27 repeats in the S-L (short to long) classification, and 27 and 34 repeats for the S-M-L2 (short to medium to very long) classification. The plasma concentrations of heme oxygenase-1 (HO-1) enzyme were measured on admission. The allele distribution in our patients was similar to that published previously, with peaks at 23 and 30 repeats. The S-allele increases AKI risk. An adjusted OR was 1.30 for each S-allele in an additive genetic model (95% CI 1.01-1.66; p = 0.041). Alleles with a repeat number greater than 34 were significantly associated with lower HO-1 concentration (p
  • Merjonen, P.; Keltikangas-Järvinen, L.; Jokela, M.; Seppälä, I.; Lyytikäinen, L.-P.; Pulkki-Råback, L.; Kivimäki, M.; Elovainio, M.; Kettunen, J.; Ripatti, S.; Kähönen, M.; Viikari, J.; Palotie, A.; Peltonen, L.; Raitakari, O. T.; Lehtimäki, T. (2011)
  • Koskinen, Lotta L. E.; Seppälä, Eija H.; Belanger, Janelle M.; Arumilli, Meharji; Hakosalo, Osmo; Jokinen, Paivi; Nevalainen, Elisa M.; Viitmaa, Ranno; Jokinen, Tarja S.; Oberbauer, Anita M.; Lohi, Hannes (2015)
    Background: Idiopathic epilepsy is a common neurological disease in human and domestic dogs but relatively few risk genes have been identified to date. The seizure characteristics, including focal and generalised seizures, are similar between the two species, with gene discovery facilitated by the reduced genetic heterogeneity of purebred dogs. We have recently identified a risk locus for idiopathic epilepsy in the Belgian Shepherd breed on a 4.4 megabase region on CFA37. Results: We have expanded a previous study replicating the association with a combined analysis of 157 cases and 179 controls in three additional breeds: Schipperke, Finnish Spitz and Beagle (p(c) = 2.9e-07, p(GWAS) = 1.74E-02). A targeted resequencing of the 4.4 megabase region in twelve Belgian Shepherd cases and twelve controls with opposite haplotypes identified 37 case-specific variants within the ADAM23 gene. Twenty-seven variants were validated in 285 cases and 355 controls from four breeds, resulting in a strong replication of the ADAM23 locus (p(raw) = 2.76e-15) and the identification of a common 28 kb-risk haplotype in all four breeds. Risk haplotype was present in frequencies of 0.49-0.7 in the breeds, suggesting that ADAM23 is a low penetrance risk gene for canine epilepsy. Conclusions: These results implicate ADAM23 in common canine idiopathic epilepsy, although the causative variant remains yet to be identified. ADAM23 plays a role in synaptic transmission and interacts with known epilepsy genes, LGI1 and LGI2, and should be considered as a candidate gene for human epilepsies.
  • Wang, Jingwen; Skoog, Tiina; Einarsdottir, Elisabet; Kaartokallio, Tea; Laivuori, Hannele; Grauers, Anna; Gerdhem, Paul; Hytonen, Marjo; Lohi, Hannes; Kere, Juha; Jiao, Hong (2016)
    High-throughput sequencing using pooled DNA samples can facilitate genome-wide studies on rare and low-frequency variants in a large population. Some major questions concerning the pooling sequencing strategy are whether rare and low-frequency variants can be detected reliably, and whether estimated minor allele frequencies (MAFs) can represent the actual values obtained from individually genotyped samples. In this study, we evaluated MAF estimates using three variant detection tools with two sets of pooled whole exome sequencing (WES) and one set of pooled whole genome sequencing (WGS) data. Both GATK and Freebayes displayed high sensitivity, specificity and accuracy when detecting rare or low-frequency variants. For the WGS study, 56% of the low-frequency variants in Illumina array have identical MAFs and 26% have one allele difference between sequencing and individual genotyping data. The MAF estimates from WGS correlated well (r = 0.94) with those from Illumina arrays. The MAFs from the pooled WES data also showed high concordance (r = 0.88) with those from the individual genotyping data. In conclusion, the MAFs estimated from pooled DNA sequencing data reflect the MAFs in individually genotyped samples well. The pooling strategy can thus be a rapid and cost-effective approach for the initial screening in large-scale association studies.
  • Univ Washington Ctr Mendelian Geno; Bootpetch, Tori C.; Hafren, Lena; Elling, Christina L.; Einarsdottir, Elisabet; Kere, Juha; Mattila, Petri S.; Santos-Cortez, Regie Lyn P. (2020)
    Otitis media (OM), a very common disease in young children, can result in hearing loss. In order to potentially replicate previously reported associations between OM and PLG, exome and Sanger sequencing, RNA-sequencing of saliva and middle ear samples, 16S rRNA sequencing, molecular modeling, and statistical analyses including transmission disequilibrium tests (TDT) were performed in a multi-ethnic cohort of 718 families and simplex cases with OM. We identified four rare PLG variants c.112A > G (p.Lys38Glu), c.782G > A (p.Arg261His), c.1481C > T (p.Ala494Val) and c.2045 T > A (p.Ile682Asn), and one common variant c.1414G > A (p.Asp472Asn). However TDT analyses for these PLG variants did not demonstrate association with OM in 314 families. Additionally PLG expression is very low or absent in normal or diseased middle ear in mouse and human, and salivary expression and microbial a-diversity were non-significant in c.1414G > A (p.Asp472Asn) carriers. Based on molecular modeling, the novel rare variants particularly c.782G > A (p.Arg261His) and c.2045 T > A (p.Ile682Asn) were predicted to affect protein structure. Exploration of other potential disease mechanisms will help elucidate how PLG contributes to OM susceptibility in humans. Our results underline the importance of following up findings from genome-wide association through replication studies, preferably using multi-omic datasets.
  • Einarsdottir, Elisabet; Svensson, Idor; Darki, Fahimeh; Peyrard-Janvid, Myriam; Lindvall, Jessica M.; Ameur, Adam; Jacobsson, Christer; Klingberg, Torkel; Kere, Juha; Matsson, Hans (2015)
    Developmental dyslexia is the most common learning disorder in children. Problems in reading and writing are likely due to a complex interaction of genetic and environmental factors, resulting in reduced power of studies of the genetic factors underlying developmental dyslexia. Our approach in the current study was to perform exome sequencing of affected and unaffected individuals within an extended pedigree with a familial form of developmental dyslexia. We identified a two-base mutation, causing a p.R229L amino acid substitution in the centrosomal protein 63 kDa (CEP63), co-segregating with developmental dyslexia in this pedigree. This mutation is novel, and predicted to be highly damaging for the function of the protein. 3D modelling suggested a distinct conformational change caused by the mutation. CEP63 is localised to the centrosome in eukaryotic cells and is required for maintaining normal centriole duplication and control of cell cycle progression. We found that a common polymorphism in the CEP63 gene had a significant association with brain white matter volume. The brain regions were partly overlapping with the previously reported region influenced by polymorphisms in the dyslexia susceptibility genes DYX1C1 and KIAA0319. We hypothesise that CEP63 is particularly important for brain development and might control the proliferation and migration of cells when those two events need to be highly coordinated.
  • Arora, G. P.; Åkerlund, M.; Brons, C.; Moen, G-H; Wasenius, N. S.; Sommer, C.; Jenum, A. K.; Almgren, P.; Thaman, R. G.; Orho-Melander, M.; Eriksson, J.; Qvigstad, E.; Birkeland, K.; Berntorp, K.; Vaag, A. A.; Groop, L.; Prasad, R. B. (2019)
    Objective Gestational diabetes mellitus (GDM) is a transient form of diabetes characterized by impaired insulin secretion and action during pregnancy. Population-based differences in prevalence exist which could be explained by phenotypic and genetic differences. The aim of this study was to examine these differences in pregnant women from Punjab, India and Scandinavia. Methods Eighty-five GDM/T2D loci in European and/or Indian populations from previous studies were assessed for association with GDM based on Swedish GDM criteria in 4018 Punjabi Indian and 507 Swedish pregnant women. Selected loci were replicated in Scandinavian cohorts, Radiel (N = 398, Finnish) and STORK/STORK-G (N = 780, Norwegian). Results Punjabi Indian women had higher GDM prevalence, lower insulin secretion and better insulin sensitivity than Swedish women. There were significant frequency differences of GDM/T2D risk alleles between both populations. rs7178572 at HMG20A, previously associated with GDM in South Indian and European women, was replicated in North Indian women. The T2D risk SNP rs11605924 in the CRY2 gene was associated with increased GDM risk in Scandinavian but decreased GDM risk in Punjabi Indian women. No other overlap was seen between GDM loci in both populations. Conclusions Gestational diabetes mellitus is more common in Indian than Swedish women, which partially can be attributed to differences in insulin secretion and action. There was marked heterogeneity in the GDM phenotypes between the populations which could only partially be explained by genetic differences.