| 1. |
- Carlsson Almlöf, Jonas, et al.
(författare)
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Contributions of de novo variants to systemic lupus erythematosus
- 2021
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Ingår i: European Journal of Human Genetics. - : Springer Nature. - 1018-4813 .- 1476-5438. ; 29:1, s. 184-193
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Tidskriftsartikel (refereegranskat)abstract
- By performing whole-genome sequencing in a Swedish cohort of 71 parent-offspring trios, in which the child in each family is affected by systemic lupus erythematosus (SLE, OMIM 152700), we investigated the contribution of de novo variants to risk of SLE. We found de novo single nucleotide variants (SNVs) to be significantly enriched in gene promoters in SLE patients compared with healthy controls at a level corresponding to 26 de novo promoter SNVs more in each patient than expected. We identified 12 de novo SNVs in promoter regions of genes that have been previously implicated in SLE, or that have functions that could be of relevance to SLE. Furthermore, we detected three missense de novo SNVs, five de novo insertion-deletions, and three de novo structural variants with potential to affect the expression of genes that are relevant for SLE. Based on enrichment analysis, disease-affecting de novo SNVs are expected to occur in one-third of SLE patients. This study shows that de novo variants in promoters commonly contribute to the genetic risk of SLE. The fact that de novo SNVs in SLE were enriched to promoter regions highlights the importance of using whole-genome sequencing for identification of de novo variants.
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| 2. |
- Farias, Fabiana H. G., et al.
(författare)
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A rare regulatory variant in the MEF2D gene affects gene regulation and splicing and is associated with a SLE sub-phenotype in Swedish cohorts
- 2019
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 27, s. 432-441
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Tidskriftsartikel (refereegranskat)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disorder with heterogeneous clinical presentation and complex etiology involving the interplay between genetic, epigenetic, environmental and hormonal factors. Many common SNPs identified by genome wide-association studies (GWAS) explain only a small part of the disease heritability suggesting the contribution from rare genetic variants, undetectable in GWAS, and complex epistatic interactions. Using targeted re-sequencing of coding and conserved regulatory regions within and around 215 candidate genes selected on the basis of their known role in autoimmunity and genes associated with canine immune-mediated diseases, we identified a rare regulatory variant rs200395694:G > T located in intron 4 of the MEF2D gene encoding the myocyte-specific enhancer factor 2D transcription factor and associated with SLE in Swedish cohorts (504 SLE patients and 839 healthy controls, p = 0.014, CI = 1.1-10). Fisher's exact test revealed an association between the genetic variant and a triad of disease manifestations including Raynaud, anti-U1-ribonucleoprotein (anti-RNP), and anti-Smith (anti-Sm) antibodies (p = 0.00037) among the patients. The DNA-binding activity of the allele was further studied by EMSA, reporter assays, and minigenes. The region has properties of an active cell-specific enhancer, differentially affected by the alleles of rs200395694:G > T. In addition, the risk allele exerts an inhibitory effect on the splicing of the alternative tissue-specific isoform, and thus may modify the target gene set regulated by this isoform. These findings emphasize the potential of dissecting traits of complex diseases and correlating them with rare risk alleles with strong biological effects.
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| 3. |
- Gustafsson Stolt, Ulrica, 1965-, et al.
(författare)
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Information and informed consent in a longitudinal screening involving children : a questionnaire survey
- 2005
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 13, s. 376-383
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Tidskriftsartikel (refereegranskat)abstract
- This empirical study explores participants' perceptions of information and understanding of their children's and their own involvement in a longitudinal screening, the ABIS Study. ABIS (All Babies In Southeast Sweden) is a multicentre, longitudinal research screening for Type 1 diabetes and multifactorial diseases involving 17 005 children and their families. For this study, a random selection of mothers was made, using perinatal questionnaire serial numbers from the ABIS study. In total, 293 of these mothers completed an anonymous questionnaire (response rate 73.3%). Our findings from the questionnaire indicate a marked difference between the reported satisfaction with and understanding of the information provided on the one hand and the significant lack of knowledge of some of the aims and methods of the ABIS screening on the other, namely concerning high-risk identification of involved children, potential prevention and future questionnaires. Two questions evoked by our results are: (1) what information is required for participants in longitudinal studies involving children? and (2) how do we ensure and sustain understanding, and thus in a prolonging, informed consent in these studies? This study underlines the importance of an increased understanding of the ethical issues that longitudinal research on children raise and the need to discuss how information and informed consent strategies should be analysed and designed in longitudinal studies.
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| 4. |
- Hmani-Aifa, Mounira, et al.
(författare)
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Identification of two new mutations in the GPR98 and the PDE6B genes segregating in a Tunisian family
- 2009
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Ingår i: EUROPEAN JOURNAL OF HUMAN GENETICS. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 17:4, s. 474-482
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Tidskriftsartikel (refereegranskat)abstract
- Autosomal recessive retinitis pigmentosa (ARRP) is a genetically heterogeneous disorder. ARRP could be associated with extraocular manifestations that define specific syndromes such as Usher syndrome (USH) characterized by retinal degeneration and congenital hearing loss (HL). The USH type II (USH2) associates RP and mild-to-moderate HL with preserved vestibular function. At least three genes USH2A, the very large G-protein-coupled receptor, GPR98, and DFNB31 are responsible for USH2 syndrome. Here, we report on the segregation of non-syndromic ARRP and USH2 syndrome in a consanguineous Tunisian family, which was previously used to define USH2B locus. With regard to the co-occurrence of these two different pathologies, clinical and genetic reanalysis of the extended family showed (i) phenotypic heterogeneity within USH2 patients and (ii) excluded linkage to USH2B locus. Indeed, linkage analysis disclosed the cosegregation of the USH2 phenotype with the USH2C locus markers, D5S428 and D5S618, whereas the ARRP perfectly segregates with PDE6B flanking markers D4S3360 and D4S2930. Molecular analysis revealed two new missense mutations, p. Y6044C and p. W807R, occurring in GPR98 and PDE6B genes, respectively. In conclusion, our results show that the USH2B locus at chromosome 3p23-24.2 does not exist, and we therefore withdraw this locus designation. The combination of molecular findings for GPR98 and PDE6B genes enable us to explain the phenotypic heterogeneity and particularly the severe ocular affection first observed in one USH2 patient. This report presents an illustration of how consanguinity could increase familial clustering of multiple hereditary diseases within the same family.
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| 5. |
- Hugot, JP, et al.
(författare)
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Clustering of Crohn's disease within affected sibships
- 2003
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 11:2, s. 179-184
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Tidskriftsartikel (refereegranskat)abstract
- Crohn's disease (CD) is a complex genetic disorder for which aetiology is unknown. Recently, genetic factors for susceptibility have been described. Several genetic loci have been mapped and partially explain the familial aggregations of the disease. However, environmental factors may also contribute to these aggregations. We considered that if the role of non-genetic factors was negligible, CD patients would be randomly distributed in sibships with multiple affected siblings. On the other hand if there was a significant environmental contribution, the siblings would be affected non-randomly over exposure status. In order to test this hypothesis, we studied 102 sibships with two or more affected siblings. A statistical test, named Cluster of Affected Sibling Test or CAST, was developed, based on the exact calculation of the probability of observing a given number of clusters of affected siblings in multiplex families. The null hypothesis of a random distribution of affected siblings was rejected (P=0,005). The observed excess of affected sibling clusters indicates that birth order influences the disease status. Considering that an adjacent order of birth is a global estimate of environmental sharing, this observation strongly suggests that environmental factors contribute to the observed familial aggregations of the disease. This observation provides evidence that familial CD is a relevant tool for further studies of environmental factors and gene-environment interaction. More generally, the CAST statistics may be widely applicable to estimate the involvement of environmental factors in the aetiology of other binary traits which may be observed in multiple members of the same sibship.
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| 6. |
- Huyghe, Jeroen R, et al.
(författare)
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A genome-wide analysis of population structure in the Finnish Saami with implications for genetic association studies
- 2011
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Ingår i: EUROPEAN JOURNAL OF HUMAN GENETICS. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 19:3, s. 347-352
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Tidskriftsartikel (refereegranskat)abstract
- The understanding of patterns of genetic variation within and among human populations is a prerequisite for successful genetic association mapping studies of complex diseases and traits. Some populations are more favorable for association mapping studies than others. The Saami from northern Scandinavia and the Kola Peninsula represent a population isolate that, among European populations, has been less extensively sampled, despite some early interest for association mapping studies. In this paper, we report the results of a first genome-wide SNP-based study of genetic population structure in the Finnish Saami. Using data from the HapMap and the human genome diversity project (HGDP-CEPH) and recently developed statistical methods, we studied individual genetic ancestry. We quantified genetic differentiation between the Saami population and the HGDP-CEPH populations by calculating pair-wise F-ST statistics and by characterizing identity-by-state sharing for pair-wise population comparisons. This study affirms an east Asian contribution to the predominantly European-derived Saami gene pool. Using model-based individual ancestry analysis, the median estimated percentage of the genome with east Asian ancestry was 6% (first and third quartiles: 5 and 8%, respectively). We found that genetic similarity between population pairs roughly correlated with geographic distance. Among the European HGDP-CEPH populations, F-ST was smallest for the comparison with the Russians (F-ST=0.0098), and estimates for the other population comparisons ranged from 0.0129 to 0.0263. Our analysis also revealed fine-scale substructure within the Finnish Saami and warns against the confounding effects of both hidden population structure and undocumented relatedness in genetic association studies of isolated populations.
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| 7. |
- Huyghe, Jeroen R., et al.
(författare)
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Genome-wide SNP analysis reveals no gain in power for association studies of common variants in the Finnish Saami
- 2010
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 18:5, s. 569-574
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Tidskriftsartikel (refereegranskat)abstract
- The Saami from Fennoscandia are believed to represent an ancient, genetically isolated population with no evidence of population expansion. Theoretical work has indicated that under this demographic scenario, extensive linkage disequilibrium (LD) is generated by genetic drift. Therefore, it has been suggested that the Saami would be particularly suited for genetic association studies, offering a substantial power advantage and allowing more economic study designs. However, no study has yet assessed this claim. As part of a GWAS for a complex trait, we evaluated the relative power for association studies of common variants in the Finnish Saami. LD patterns in the Saami were very similar to those in the non-African HapMap reference panels. Haplotype diversity was reduced and, on average, levels of LD were higher in the Saami as compared with those in the HapMap panels. However, using a 'hidden' SNP approach we show that this does not translate into a power gain in association studies. Contrary to earlier claims, we show that for a given set of common SNPs, genomic coverage attained in the Saami is similar to that in the non-African HapMap panels. Nevertheless, the reduced haplotype diversity could potentially facilitate gene identification, especially if multiple rare variants play a role in disease etiology. Our results further indicate that the HapMap is a useful resource for genetic studies in the Saami.
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| 8. |
- Johansson, Josefin, et al.
(författare)
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Gustavson syndrome is caused by an in-frame deletion in RBMX associated with potentially disturbed SH3 domain interactions
- 2024
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 32:3, s. 333-341
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Tidskriftsartikel (refereegranskat)abstract
- RNA binding motif protein X-linked (RBMX) encodes the heterogeneous nuclear ribonucleoprotein G (hnRNP G) that regulates splicing, sister chromatid cohesion and genome stability. RBMX knock down experiments in various model organisms highlight the gene's importance for brain development. Deletion of the RGG/RG motif in hnRNP G has previously been associated with Shashi syndrome, however involvement of other hnRNP G domains in intellectual disability remain unknown. In the current study, we present the underlying genetic and molecular cause of Gustavson syndrome. Gustavson syndrome was first reported in 1993 in a large Swedish five-generation family presented with profound X-linked intellectual disability and an early death. Extensive genomic analyses of the family revealed hemizygosity for a novel in-frame deletion in RBMX in affected individuals (NM_002139.4; c.484_486del, p.(Pro162del)). Carrier females were asymptomatic and presented with skewed X-chromosome inactivation, indicating silencing of the pathogenic allele. Affected individuals presented minor phenotypic overlap with Shashi syndrome, indicating a different disease-causing mechanism. Investigation of the variant effect in a neuronal cell line (SH-SY5Y) revealed differentially expressed genes enriched for transcription factors involved in RNA polymerase II transcription. Prediction tools and a fluorescence polarization assay imply a novel SH3-binding motif of hnRNP G, and potentially a reduced affinity to SH3 domains caused by the deletion. In conclusion, we present a novel in-frame deletion in RBMX segregating with Gustavson syndrome, leading to disturbed RNA polymerase II transcription, and potentially reduced SH3 binding. The results indicate that disruption of different protein domains affects the severity of RBMX-associated intellectual disabilities.
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| 9. |
- Karlsson, Andreas O, et al.
(författare)
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Y-chromosome diversity in Sweden - A long-time perspective
- 2006
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 14:8, s. 963-970
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Tidskriftsartikel (refereegranskat)abstract
- Sixteen Y-chromosomal binary markers and nine Y-chromosome short tandem repeats were analyzed in a total of 383 unrelated males from seven different Swedish regions, one Finnish region and a Swedish Saami population in order to address questions about the origin and genetic structure of the present day population in Sweden. Haplogroup l1a* was found to be the most common haplogroup in Sweden and accounted, together with haplogroups R1b3, R1a1 and N3, for over 80% of the male lineages. Within Sweden, a minor stratification was found in which the northern region Vasterbotten differed significantly (P less than 0.05) from the other Swedish regions. A flow of N3 chromosomes into Vasterbotten mainly from Saami and Finnish populations could be one explanation for this stratification. However, the demographic history of Vasterbotten involving a significant male absence during the 17th Century may also have had a large impact. Immigration of young men from elsewhere to Varmland at the same time, can be responsible for a similar deviation with I1a* haplotypes. Y chromosomes within haplogroup R1b3 were found to have the highest STR variation among all haplogroups and could thus be considered to be one of the earliest major male lineages present in Sweden. Regional haplotype variation, within R1b3, also showed a difference between two regions in the south of Sweden. This can also be traced from historical time and is visible in archaeological material Overall this Y chromosome study provides interesting information about the genetic patterns and demographic events in the Swedish population
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| 10. |
- Paneque, Milena, et al.
(författare)
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Complementarity between medical geneticists and genetic counsellors: its added value in genetic services in Europe
- 2017
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Ingår i: European Journal of Human Genetics. - : NATURE PUBLISHING GROUP. - 1018-4813 .- 1476-5438. ; 25:8, s. 918-923
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Tidskriftsartikel (refereegranskat)abstract
- Clinical genetic services have progressed significantly the last few decades. This has led to the need for non-medical health-care professionals working as genetic counsellors in Europe and worldwide. However, there is no unified approach to genetic counsellors role in health-care services in Europe, as in most countries the profession is still emerging and the educational backgrounds diverge noticeably, within and between countries. This qualitative study aims to describe the potential added value of genetic counsellors in clinical genetics teams and to explore their tasks and responsibilities in different European countries. A total of 143 participants providing genetic counselling in Europe at the time of the survey responded. The results show differences in activities of genetic counsellors, although there is a wide range of roles, which are similar. The ability to establish a quality relationship with consultands was frequently mentioned as one of the strengths of genetic counsellors, as well as a patient-centred approach. It is believed that genetic counsellors add a more holistic approach of psychosocial and familial dimensions of genetic concerns to the multidisciplinary teams. This study provides examples of successful integration of genetic counsellors in teams, as complementariness with medical geneticist became clear in several cases. Although the added value of genetic counsellors was manifested, professional recognition of genetic counsellors across Europe is still needed in order to support the quality of patients care and safety of practice.
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