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- Zhang, G., et al.
(author)
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Genetic Associations with Gestational Duration and Spontaneous Preterm Birth
- 2017
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In: New England Journal of Medicine. - 0028-4793. ; 377:12, s. 1156-1167
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Journal article (peer-reviewed)abstract
- BACKGROUND Despite evidence that genetic factors contribute to the duration of gestation and the risk of preterm birth, robust associations with genetic variants have not been identified. We used large data sets that included the gestational duration to determine possible genetic associations. We performed a genomewide association study in a discovery set of samples obtained from 43,568 women of European ancestry using gestational duration as a continuous trait and term or preterm (< 37 weeks) birth as a dichotomous outcome. We used samples from three Nordic data sets (involving a total of 8643 women) to test for replication of genomic loci that had significant genomewide association (P< 5.0x10(-8)) or an association with suggestive significance (P< 1.0x10(-6)) in the discovery set. In the discovery and replication data sets, four loci (EBF1, EEFSEC, AGTR2, and WNT4) were significantly associated with gestational duration. Functional analysis showed that an implicated variant in WNT4 alters the binding of the estrogen receptor. The association between variants in ADCY5 and RAP2C and gestational duration had suggestive significance in the discovery set and significant evidence of association in the replication sets; these variants also showed genomewide significance in a joint analysis. Common variants in EBF1, EEFSEC, and AGTR2 showed association with preterm birth with genomewide significance. An analysis of mother-infant dyads suggested that these variants act at the level of the maternal genome. In this genomewide association study, we found that variants at the EBF1, EEFSEC, AGTR2, WNT4, ADCY5, and RAP2C loci were associated with gestational duration and variants at the EBF1, EEFSEC, and AGTR2 loci with preterm birth. Previously established roles of these genes in uterine development, maternal nutrition, and vascular control support their mechanistic involvement.
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- Huusko, Johanna M, et al.
(author)
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Whole exome sequencing reveals HSPA1L as a genetic risk factor for spontaneous preterm birth.
- 2018
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In: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 14:7
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Journal article (peer-reviewed)abstract
- Preterm birth is a leading cause of morbidity and mortality in infants. Genetic and environmental factors play a role in the susceptibility to preterm birth, but despite many investigations, the genetic basis for preterm birth remain largely unknown. Our objective was to identify rare, possibly damaging, nucleotide variants in mothers from families with recurrent spontaneous preterm births (SPTB). DNA samples from 17 Finnish mothers who delivered at least one infant preterm were subjected to whole exome sequencing. All mothers were of northern Finnish origin and were from seven multiplex families. Additional replication samples of European origin consisted of 93 Danish sister pairs (and two sister triads), all with a history of a preterm delivery. Rare exonic variants (frequency <1%) were analyzed to identify genes and pathways likely to affect SPTB susceptibility. We identified rare, possibly damaging, variants in genes that were common to multiple affected individuals. The glucocorticoid receptor signaling pathway was the most significant (p<1.7e-8) with genes containing these variants in a subgroup of ten Finnish mothers, each having had 2-4 SPTBs. This pathway was replicated among the Danish sister pairs. A gene in this pathway, heat shock protein family A (Hsp70) member 1 like (HSPA1L), contains two likely damaging missense alleles that were found in four different Finnish families. One of the variants (rs34620296) had a higher frequency in cases compared to controls (0.0025 vs. 0.0010, p = 0.002) in a large preterm birth genome-wide association study (GWAS) consisting of mothers of general European ancestry. Sister pairs in replication samples also shared rare, likely damaging HSPA1L variants. Furthermore, in silico analysis predicted an additional phosphorylation site generated by rs34620296 that could potentially affect chaperone activity or HSPA1L protein stability. Finally, in vitro functional experiment showed a link between HSPA1L activity and decidualization. In conclusion, rare, likely damaging, variants in HSPA1L were observed in multiple families with recurrent SPTB.
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- Virtanen, S M, et al.
(author)
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Feasibility and compliance in a nutritional primary prevention trial in infants at increased risk for type 1 diabetes
- 2011
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In: ACTA PAEDIATRICA. - : Blackwell Publishing Ltd. - 0803-5253. ; 100:4, s. 557-564
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Journal article (peer-reviewed)abstract
- Aim: The international Trial to Reduce IDDM in the Genetically at Risk (TRIGR) was launched to determine whether weaning to a highly hydrolysed formula in infancy reduces the incidence of type 1 diabetes in children at increased genetic disease susceptibility. We describe here the findings on feasibility and compliance from the pilot study. Methods: The protocol was tested in 240 children. The diet of the participating children was assessed by self-administered dietary forms, a structured questionnaire and a food record. Blood samples were taken and weight and height measured at birth and at 3, 6, 9, 12, 18 and 24 months. Results: A majority of the subjects (84%) were exposed to the study formula at least for 2 months. Linear growth or weight gain over the first 2 years of life was similar in the two study groups. The levels of IgA and IgG antibodies to cows milk and casein were higher in the cows milk-based formula group than in the hydrolysed formula group during the intervention period (p andlt; 0.05), reflecting the difference in the intake of cows milk protein. Conclusion: This randomized trial on infant feeding turned out to be feasible, and dietary compliance was acceptable. Valuable experience was gained for the planning and sample size estimation of the study proper.
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- Åkerblom, Hans, et al.
(author)
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Dietary manipulation of beta cell autoimmunity in infants at increased risk of type 1 diabetes : A pilot study
- 2005
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In: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 48:5, s. 829-837
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Journal article (peer-reviewed)abstract
- Aims/hypothesis: We aimed to assess the feasibility of a dietary intervention trial with weaning to hydrolysed formula in infants at increased risk of type 1 diabetes and to study the effect of the intervention on the emergence of diabetes-associated autoantibodies in early childhood. Methods: We studied 242 newborn infants who had a first-degree relative with type 1 diabetes and carried risk-associated HLA-DQB1 alleles. After exclusive breastfeeding, the infants underwent a double-blind, randomised pilot trial of either casein hydrolysate (Nutramigen, Mead Johnson) or conventional cow's milk-based formula until the age of 6-8 months. During a mean observation period of 4.7 years, autoantibodies to insulin, anti-glutamic acid decarboxylase and insulinoma-associated antigen-2 were measured by radiobinding assays, and islet cell antibodies (ICA) by immunofluorescence. Results: The feasibility of screening and identifying a cohort of first-degree relatives with HLA-conferred disease susceptibility, enrolling them in a dietary intervention trial and following them for seroconversion to autoantibody positivity is established. The cumulative incidence of autoantibodies was somewhat smaller in the casein hydrolysate vs control formula group, suggesting the need for a larger well-powered study. After adjustment for duration of study formula feeding, life-table analysis showed a significant protection by the intervention from positivity for ICA (p=0.02) and at least one autoantibody (p=0.03). Conclusions/interpretation: The present study provides the first evidence ever in man, despite its limited power, that it may be possible to manipulate spontaneous beta cell autoimmunity by dietary intervention in infancy. © Springer-Verlag 2005.
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