https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Integration of EpiSign, facial phenotyping, and likelihood ratio interpretation of clinical abnormalities in the re-classification of an ARID1B missense variant https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54895 Wed 20 Mar 2024 13:33:17 AEDT ]]> Genetic variation affecting DNA methylation and the human imprinting disorder, Beckwith-Wiedemann syndrome https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45953 T was more prevalent in BWS with KCNQ1OT1 TSS-DMR LOM (p < 0.017); however, the relationship was not significant when the Bonferroni correction for multiple testing was applied (significance, p = 0.0036). None of the remaining 13 SNVs were significantly different in the two populations tested. The DNMT1 locus was screened in 53 BWS cases, and three rare missense variants were identified in each of three patients: rs138841970: C>T, rs150331990: A>G and rs757460628: G>A encoding NP_001124295 p.Arg136Cys, p.His1118Arg and p.Arg1223His, respectively. These variants have population frequencies of less than 1 in 1000 and were absent from 100 control cases. Functional characterization using a hemimethylated DNA trapping assay revealed a reduced methyltransferase activity relative to wild-type DNMT1 for each variant ranging from 40 to 70% reduction in activity. Conclusions: This study is the first to examine folate pathway genetics in BWS and to identify rare DNMT1 missense variants in affected individuals. Our data suggests that reduced DNMT1 activity could affect maintenance of methylation at KCNQ1OT1 TSS-DMR in some cases of BWS, possibly via a maternal effect in the early embryo. Larger cohort studies are warranted to further interrogate the relationship between impaired MTHFR enzymatic activity attributable to MTHFR rs1801133: C>T, dietary folate intake and BWS.]]> Tue 08 Nov 2022 14:51:28 AEDT ]]>