title: A simple screening method for detection of Klinefelter syndrome and other X-chromosome aneuploidies based on copy number of the androgen receptor gene.
abstract: Due to the high prevalence and variable phenotype of patients with Klinefelter syndrome, there is a need for a robust and rapid screening method allowing early diagnosis. Here, we report on the development and detailed clinical validation of a quantitative real-time PCR (qPCR)-based method of the copy number assessment of the androgen receptor (AR) gene, located to Xq11.2-q12. We analysed samples from 50 individuals, including a healthy male and female controls and patients with Klinefelter syndrome (47,XXY; 48,XXXY) (n = 28), mosaicisms (46,XX/47,XXY/48XXYY; 45,X/46,XY) (n = 3), other sex chromosome abnormalities (46,XX males; 47,XYY)(n = 4) and normal karyotypes (46,XY) (n = 13). The reference range for the AR-copy number was established as 0.8-1.2 for one copy and 1.7-2.3 for two copies. The qPCR results were within the reference range in 17/18 samples (94%) or 30/31 (97%) samples with one or two copies of the AR gene, respectively. None of the Klinefelter patients were misdiagnosed as having a karyotype with only one X-chromosome, and in none of the 46,XY males were two copies demonstrated. We systematically compared qPCR results with those obtained with another PCR-based method, the XIST-gene expression. The XIST-expression based assay was correct in only 29/36 samples (81%). Our findings demonstrated that the AR-qPCR technique is a simple and reliable screening method for diagnosis of patients with Klinefelter syndrome or other chromosomal disorders involving an aberrant number of X-chromosomes.
authors.affiliation: Department of Growth and Reproduction, Juliane Marie Centre, Section GR-5064, The National University Hospital of Copenhagen, DK-2100, Copenhagen, Denmark. anne.marie.ottesen@rh.regionh.dk
authors.forename: A M
authors.initials: AM
authors.lastname: Ottesen
authors.forename: I D
authors.initials: ID
authors.lastname: Garn
authors.forename: L
authors.initials: L
authors.lastname: Aksglaede
authors.forename: A
authors.initials: A
authors.lastname: Juul
authors.forename: E
authors.initials: E
authors.lastname: Rajpert-De Meyts
mesh_terms: D000782:Aneuploidy; D041321:Chromosomes, Human, X / Q000235:genetics*; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D007713:Klinefelter Syndrome / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D011944:Receptors, Androgen / Q000235:genetics*
chemical_list: D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D011944:Receptors, Androgen; C077885:XIST non-coding RNA