title: Methylation of AR locus does not always reflect X chromosome inactivation state.
abstract: Clonality can be established by a lack of mosaicism in a female because of random inactivation of either the maternal or paternal X chromosome early in embryogenesis. The methylation status of CpG sites close to the trinucleotide repeats in exon 1 of the human androgen receptor (AR) X chromosome gene assay (HUMARA) has been used to determine clonality. This HUMARA at times indicated clonal hematopoiesis in healthy elderly women, thus precluding its applicability. We used a clonality assay based on quantitative expression of polymorphic X chromosome genes (qTCA) and found no evidence of clonal hematopoiesis in healthy nonanemic elderly persons. We found instances of discordance between HUMARA results and those obtained by pyrosequencing and qTCA methods, as well as by directly quantifying AR gene expression. To determine the basis of this discrepancy we examined the methylation pattern of the AR locus subject to HUMARA. Notably, we found the extent of DNA methylation to be highly variable at the AR gene in granulocytes of persons with discordant results and also in erythroid burst-forming unit colonies but not in those with clonal hematopoiesis. These data provide the molecular basis of incomplete correlation with the pattern of DNA methylation of this X chromosome AR gene locus.
authors.affiliation: Department of Medicine, Division of Hematology, University of Utah School of Medicine Salt Lake City, UT 84132, USA.
authors.forename: Sabina I
authors.initials: SI
authors.lastname: Swierczek
authors.forename: Lucie
authors.initials: L
authors.lastname: Piterkova
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Jelinek
authors.forename: Neeraj
authors.initials: N
authors.lastname: Agarwal
authors.forename: Sue
authors.initials: S
authors.lastname: Hammoud
authors.forename: Andrew
authors.initials: A
authors.lastname: Wilson
authors.forename: Kimberly
authors.initials: K
authors.lastname: Hickman
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Parker
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Cairns
authors.forename: Bradley
authors.initials: B
authors.lastname: Cairns
authors.forename: Josef T
authors.initials: JT
authors.lastname: Prchal
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D041321:Chromosomes, Human, X / Q000235:genetics / Q000378:metabolism; D060965:Clonal Evolution / Q000235:genetics; D019175:DNA Methylation / Q000502:physiology; D005260:Female; D005787:Gene Frequency; D056426:Genetic Loci; D005838:Genotype; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D008297:Male; D009196:Myeloproliferative Disorders / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA / Q000379:methods; D018911:Trinucleotide Repeats / Q000235:genetics; D049951:X Chromosome Inactivation / Q000235:genetics* / Q000502:physiology
chemical_list: C410798:AR protein, human; D011944:Receptors, Androgen; C507924:JAK2 protein, human; D053614:Janus Kinase 2