Search results for "X chromosome"
showing 10 items of 80 documents
Sex reversal from functional disomy of Xp: Prenatal and post-mortem findings.
2008
Translocations involving the short arms of the X and Y chromosomes are uncommon and are often associated with anomalies in gonadal development. Segmental duplications of the X chromosome interfere with the formation of the testis in patients with a 46,XY karyotype. The gene products located within the duplicated segment, when present in double dose, may affect on male sex development. We report on a fetus with karyotype 46,XY,der (14)t(X;14) (p10;p10)dn. Attached to chromosome 14 is the entire short arm of the X chromosome. Therefore, the fetus is affected with a disomy of Xp, resulting in complete male to female sex reversal, as well as other structural defects. To the best of our knowledg…
FISH mapping of the sex-reversal region on human chromosome 9p in two XY females and in primates
2000
Accumulating evidence suggests that haploinsufficiency of a dosage-sensitive gene(s) in human chromosome 9p24.3 is responsible for the failure of testicular development and feminisation in XY patients with monosomy for 9p. We have used molecular cytogenetic methods to characterise the sex-reversing 9p deletions in two XY females. Fluorescence in situ hybridisation (FISH) with YACs from the critical 9p region containing an evolutionarily conserved sex-determining gene, DMRT1, is a very fast and reliable assay for patient screening. Comparative YAC mapping on great ape and Old and New World monkey chromosomes demonstrated that the critical region was moved from an interstitial position on the…
GH successful treatment in a female with a de novo 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2), growth impairment and SHOX-haploinsufficiency
2019
Abstract Children with chromosome translocations, concerning X chromosome, have a genetic pattern different from Turner syndrome; however, when a translocation involves the of part of X chromosome including short stature homeobox-containing Sex-determining Region Y gene, growth may be severely compromised. We describe the clinical case of a 2.2-year-old-female, arrived at our paediatric unit for a decrease of height velocity. The karyotype was 46,XX,add(X)(p36.3). Array comparative genomic hybridization showed a fragment of Y chromosome, extended from 8.803.981 (Yp11.2) to 28.767.604 (Yq11.23). The final karyotype was 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2). Fluorescence in situ Hybridization…
Aneuploidy as a consequence of senescence and ovariectomy in the golden hamster (Mesocricetus auratus).
1978
The hypothesis of the preferred X-chromosome loss in elder human females was reevaluated in the golden hamster: early castration of females proved that the increase of aneuploid cells is correlated with the loss of the ovaries. But here, and in old females, aneuploidy consisted of random loss of excess of chromosomes, in no case an X-chromosome.
The Molecular Basis of X-Linked Spondyloepiphyseal Dysplasia Tarda
2001
The X-linked form of spondyloepiphyseal dysplasia tarda (SEDL), a radiologically distinct skeletal dysplasia affecting the vertebrae and epiphyses, is caused by mutations in the SEDL gene. To characterize the molecular basis for SEDL, we have identified the spectrum of SEDL mutations in 30 of 36 unrelated cases of X-linked SEDL ascertained from different ethnic populations. Twenty-one different disease-associated mutations now have been identified throughout the SEDL gene. These include nonsense mutations in exons 4 and 5, missense mutations in exons 4 and 6, small (2–7 bp) and large (>1 kb) deletions, insertions, and putative splicing errors, with one splicing error due to a complex deleti…
A sequence motif enriched in regions bound by the Drosophila dosage compensation complex
2010
Abstract Background In Drosophila melanogaster, dosage compensation is mediated by the action of the dosage compensation complex (DCC). How the DCC recognizes the fly X chromosome is still poorly understood. Characteristic sequence signatures at all DCC binding sites have not hitherto been found. Results In this study, we compare the known binding sites of the DCC with oligonucleotide profiles that measure the specificity of the sequences of the D. melanogaster X chromosome. We show that the X chromosome regions bound by the DCC are enriched for a particular type of short, repetitive sequences. Their distribution suggests that these sequences contribute to chromosome recognition, the genera…
Global patterns of sequence evolution in Drosophila.
2007
This article is available from: http://www.biomedcentral.com/1471-2164/8/408
Aneiploīdija, dzimumhromosomu izmaiņas un mejotisko gēnu ekspresija vīriešu ļaundabīgajos audzējos: Iespējamā mejotiskā izcelsme
2017
Novērots, ka vairākos vēža tipos DNS sadalījums para-triploīdajā diapazonā (ap 69 hromosomām) ir bieži saistīts ar lielāku ļaundabīgumu, paaugstinātu rezistenci pret ķīmijterapiju un nelabvēlīgu prognozi pacientam. Šobrīd vadošā teorija uzskata, ka triploīdās vēža šūnas veidojas no tetraploīdajām nejaušo anomālo mitožu sērijas rezultātā. Tomēr jaunākie novērojumi liecina, ka triploīdijas rašanās var nebūt pilnīgi nejauša un ka tā varētu būt iesaistīta vēža attīstības svarīgākajās stadijās. Sakarā ar jaunākajiem novērojumiem par to, kādu lomu spēlē vēža cilmes šūnas audzēju pašatjaunošanās procesā, zinātnieki sāka atkārtoti pievērsties 19. gadsimta teorijai, kura uzskata, ka vēža šūnu evolūc…
The banding pattern of polytene chromosomes of Drosophila guanche compared with that of D. subobscura.
1987
A detailed map of the salivary gland chromosomes of Drosophila guanche is presented and compared to the standard gene arrangements of D. subobscura. Generally, the polytene chromosomc banding patterns of the two species show a high degrce of homology. Only Segment I of the sex chromosome (Chromosome A) shows marked differences. The banding pattern proposed for this segment in D. guanche could have originated from a cluster of overlapping inversions including A1 arrangement.
Molecular Analysis of the Androgen Receptor Gene in 52 Patients with Complete or Partial Androgen Insensitivity Syndrome: A Collaborative Study
1992
In patients with androgen insensitivity syndrome (AIS), RFLP study of the androgen receptor gene made it possible to analyze whether deletions or mutations could be responsible for abnormalities in androgen responsiveness. We studied RFLPs of DNA from 25 46,XY patients with partial AIS (PAIS), defined as a concentration of androgen receptor in genital-skin fibroblasts less than 340 fmol/mg DNA, and DNA from 27 46,XY patients with complete AIS (CAIS) with no detectable androgen receptor site. DNA samples were digested with BamHI, EcoRI, HindIII and TaqI restriction enzymes and hybridized with three cDNA probes covering the three domains of the androgen receptor. When we had the maternal and …