The phenotypic variations of multi-locus imprinting disturbances associated with maternal-effect variants of NLRP5 range from overt imprinting disorder to apparently healthy phenotype

摘要

Novel variants in a familial case of MLID with phenotypically discordant siblings. Domain structure of human NLRP5 depicting the position of known variants [ , , ], along with the two novel variants described in the present study (indicated by red circles). Family pedigree and corresponding NLRP5 mutations. Black-filled symbols represent individuals with evident BWS features: proband (III-1) and fetus with omphalocele. Carriers of variants are indicated by symbols with central dot (red in case of maternal carriers). Weeks of gestation are indicated for the four aborted fetuses. Boxplot showing DNA methylation analysis of four maternal gDMRs ( , , GNAS, and ) and one paternal gDMR ( ), as measured by bisulphite pyrosequencing in three different tissue types. Primers used in PCR and sequencing have been checked for specificity of the assay. For each region, 6-12 CpGs have been tested and distribution of their percentage of methylation has been represented as boxplot. Data are a mean between at least two independent PCR and pyrosequencing experiments. Controls include 4–6 normal individuals. values have been calculated by two-tailed Student’s test (* ≤ 0.05; ** ≤ 0.01; *** ≤ 0.001; **** ≤ 0.0001). Validation of variants by Sanger sequencing and their segregation in the family. Variants are highlighted with a blue-shaded stripe and their genomic positions are indicated below the chromatogram (chr19, GRCh37/hg19). Note that the maternal grandmother (I-2) was heterozygous for the missense variant while the mother (II-2) was compound heterozygous for both the missense and nonsense variants