Publications by authors named "Jonathan L A Callaway"

Background: Approximately 1 in 1000 men have a 47,XYY karyotype. Previous publications have presented cases of infertile XYY men and have suggested that the additional Y chromosome may cause disrupted meiosis leading to sperm apoptosis. The purpose of the current study was to determine whether XYY men are over-represented in infertility cohorts.

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Our aim was to construct a streamlined technical workflow to facilitate a prospective, multi-centre evaluation of array comparative genomic hybridisation (array-CGH) in the prenatal diagnostic context. A collection of commercially available DNA extraction and quantification techniques were evaluated and compared using minimal quantities of amniotic fluid, chorionic villi and cultured cells. When prenatal DNA of suitable quality and quantity was obtained, array-CGH was performed using Oxford Gene Technology's (OGT, Oxford, UK) CytoSure™ ISCA 8 × 60 K oligo array platform.

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The clinical utility of microarray technologies when used in the context of prenatal diagnosis lies in the technology's ability to detect submicroscopic copy number changes that are associated with clinically significant outcomes. We have carried out a systematic review of the literature to calculate the utility of prenatal microarrays in the presence of a normal conventional karyotype. Amongst 12,362 cases in studies that recruited cases from all prenatal ascertainment groups, 295/12,362 (2.

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Background: In recent studies, partial deletions of the azoospermia factor c region (AZFc) on the Y-chromosome have been detected in males with infertility problems. However, there has been a lot of debate about their significance. In order to study such deletions, a simple but accurate method for their detection was applied in this study.

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This study was an investigation of 79 patients referred to the Wessex Regional Genetics Laboratory with suspected Russell-Silver Syndrome or unexplained short stature/intra uterine growth restriction, warranting genetic investigation. Methylation status was analysed at target sequences within eleven imprinted loci (PLAGL1, IGF2R, PEG10, MEST1, GRB10, KCNQ1OT1, H19, IGF2P0, DLK1, PEG3, NESPAS). Thirty seven percent (37%) (29 of 79) of samples were shown to have a methylation abnormality.

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We have previously described individuals presenting with transient neonatal diabetes and showing a variable pattern of DNA hypomethylation at imprinted loci throughout the genome. We now report mutations in ZFP57, which encodes a zinc-finger transcription factor expressed in early development, in seven pedigrees with a shared pattern of mosaic hypomethylation and a conserved range of clinical features. This is the first description of a heritable global imprinting disorder that is compatible with life.

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