1,721,074 research outputs found
Current controversies in prenatal diagnosis 3: is conventional chromosome analysis necessary in the post-array CGH era?
No full textArray technology in prenatal diagnosis
No full textArray technology, here termed molecular karyotyping, is an attractive alternative to conventional karyotyping for prenatal diagnosis given the increase in resolution as well as faster report times. We review the benefits and limitations of this technique for the detection of pathogenic genomic imbalances, address the challenges raised in the interpretation of copy number variations, discuss practical considerations for the routine implementation of molecular karyotyping in prenatal diagnosis, and identify areas where more research is desired to enable large scale introduction of the technique(s)
A newborn with ambiguous genitalia and a complex X;Y rearrangement.
No full textIn most mammals, sex is determined at the beginning of gestation by the constitution of the sex chromosomes, XY in males and XX in females.
CASE:
Here we report an interesting case characterized by ambiguous genitalia and ovotestis in a newborn carrying an apparently female karyotype (46 XX). Array Comparative Genomic Hybridization (Array-CGH) revealed an unbalanced rearrangement resulting in the deletion of the distal Xp and the duplication of the proximal Xp contiguous region with presence of the Y chromosome from Ypter to Yq11. Fluorescent in situ hybridization (FISH) showed that this portion of the Y was translocated to the tip of the abnormal X and that the duplicated portion of chromosome X was inverted. Altogether, the abnormal chromosome was a dicentric one with the centromere of the Y chromosome apparently inactivated.
CONCLUSION:
The presence within the translocated Y chromosome of the SRY gene explains the devolopment of testes although it is not clear the reason for the genitalia ambiguity
PRKACB and Carney complex
No full textWe report the case of a young woman with Carney complex who presented at 19 years of age with acromegaly, pigmented spots, and myxomas. She did not have Cushing's syndrome. Treatment of her pituitary tumor arrested the acromegaly. At age 24, weight, menstrual cycles, and cortisol levels were normal. Sequencing of her DNA did not reveal PRKAR1A or PRKACA mutations. A genomewide study identified a 1.6-Mb triplication of chromosome 1p31.1, including PRKACB, which codes for catalytic subunit beta (Cβ), the second most important catalytic subunit of PKA
First trimester diagnosis of 13q-syndrome associated with increased fetal nuchal translucency thickness. Clinical findings and systematic review.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
APC rearrangements in familial adenomatous polyposis: heterogeneity of deletion lengths and breakpoint sequences underlies similar phenotypes
No full textFamilial adenomatous polyposis (FAP) is a dominantly inherited syndrome leading to the development of multiple intestinal polyps and colorectal cancer. FAP is associated with germline defects of APC tumor suppressor gene; although truncating mutations account for the majority of cases, large APC deletions represent a common disease-causing defect. While a number of intragenic deletions have been well-characterized, sequencing data of breakpoints involved in large APC rearrangements are extremely scanty. We characterized six deletions identified by multiplex ligation-dependent probe amplification (three intragenic and three larger deletions encompassing the APC locus): in each case, we precisely mapped the breakpoints by array-comparative genomic hybridization and/or long-range PCR followed by sequencing. All rearrangements were novel and no rearrangements proved to be recurrent or clustered. The three intragenic deletions involved exons 4, 9 and 14, respectively; larger deletions (30,444, 265,471 and 921,295 bp in length) involved APC as well as adjacent genes. Nine out of 12 breakpoints fell within repetitive elements (5 Alu, 2 LINE, 1 Tigger and 1 MIR), while the remaining 3 fell within unique sequences. In five out of six patients, non-allelic homologous recombination or non-homologous end joining appear as the most likely mechanisms behind APC rearrangements. Although a certain variability of clinical features was detectable both between and within families with deletions, all deletion carriers were classifiable as FAP patients showing colonic and extracolonic manifestations that belong to the spectrum of the syndrome. Therefore, different sized deletions, variable breakpoint localizations and haploinsufficiency for other genes besides APC, resulted in the same FAP clinical phenotype
A prenatal case of duplication with terminal deletion of 5p not identified by conventional cytogenetics
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