Mol Syndromol. May;8(3) doi: / Epub Feb Maternal Uniparental Disomy 14 (Temple Syndrome) as a Result of a. La disomía uniparental es una patología en la cual las dos copias de un cromosoma son heredadas de un mismo progenitor, en lugar de que. La disomía uniparental hace referencia a la situación en la que las dos copias de un cromosoma provienen del mismo progenitor, en lugar de que una copia.
|Published (Last):||7 October 2005|
|PDF File Size:||19.68 Mb|
|ePub File Size:||16.12 Mb|
|Price:||Free* [*Free Regsitration Required]|
Retrieved 29 February UPD can occur as a random event during the formation of egg or sperm cells or may happen in early fetal development. This slide shows a source to find more information from a book written witn my friend and Colleague Stylianos Emmanuel Antonarakis which was published in by Liss-Wiley in New York.
Dealing in more details into this siuation, we see that eggs with the segregation of this homologous centric fusion can, upon fertilization, only produce monosomic or trisomic 22 inviable abortion products! Three other pairs came under suspicion of exercising harmful effects through a similar mechanism, although such an interference appears less and less certain for maternal chromosome 2, still quite likely for maternal chromosome 16 and definite for chromosome 20, both paternal and maternal, a topic in full evolution.
It is precisely at this junction that I would like to review the list of some thirty or so different recessive conditions traced to this very mechanism over the last 14 years.
Indeed this very observation was to serve at the introduction of a still poorly understood phenomenon, genomic imprinting. Other notable discoveries occurred in the sixties in our field, including the sighting of some tiny deletions, but, just as happened in the early years of photography, the chromosomes appeared uniformely dark over a clear white background.
For example, either isodisomy or heterodisomy can disrupt parent-specific genomic imprintingresulting in imprinting disorders. In this diagram from our book, individual 3 has an allele from each parent, as normal and individuals 4 and 5 have only paternal alleles, two contrasted ones for individual 4i.
This slide shows what proportion of some well defined syndromes might be caused by a given uniparental pair proven responsible for disrupting the normal imprinting process. Spinal muscular atrophy III juvenil type. The obvious lesson to it was that an intact second maternal 15 could not substitute successfully for the missing paternal one.
Identification of human chromosomes by DNA-binding fluorescent agents. Early genetic diagnosis permits a specific follow-up of children with upd 14 mat in order to optimize the long-term outcome.
I have selected these examples because, to me, they illustrate some incredible twists of Nature. In this context, the opportunity of using a few drops of venous blood for short term culture and chromosome studies with Phytohemagglutinin for blast tranformation of monolymphocytes represented a boon to all interested personnel. Thank you, indeed for your hospitality. You see here, at first glance, a non-homologous balanced translocation which, through an adjacent meiotic separation, produces a disomic gamete.
Orphanet: Disomia uniparental del cromosoma 15 de origen paterno UPDP15
And this is precisely the mechanism which helped these investigators to uncover the first thoroughly analyzed and described case of UPD. Cystic fibrosis and Kartagener syndrome. Within two of these years, andthe three major autosomal trisomies, G, E, and D, namely 21, 18 and 13 turned up along with three of the four more common sex chromosome anomalies.
We only see a few in the first decade following publication of the concept.
Maternal uniparental disomy of chromosome 14 upd 14 mat or Temple syndrome is an imprinting disorder associated with a relatively mild phenotype. Herlitz junctional epidermolysis bullosa. When interstitial, the segmental UPD results from two symmetrical breaks, which are shown here as the result of an interchromatid kiss! These karyotypic anomalies chiefly stem from meiotic errors affecting the distribution of the chromosomes in one of two gametes.
Such a luck in this case will not occur at the next generation in spite of 7 trials ending in as many abortions. Both these slides show the pace at which these uniparental pairs were uncovered since the first uniparentall were identified.
Maternal Uniparental Disomy 14 (Temple Syndrome) as a Result of a Robertsonian Translocation.
She, in turn, produces a balanced male offspring born after 5 spontaneous abortions. On this next slide, we show somewhat arbitrarily the chromosome numbers, maternal or paternal, which have contributed a monoparental pair in the make up of one purely and disomi diploid genome, assuming that the available information allowed an exclusion of the mosaic compounded by an aneuploid component.
This summary slide attempts to compile the information developed in this presentation.
On ths slide, precisely, a pattern of homologous centric fusion for chromosome 22 is found in a woman who aborts ten times in a row before producing a normal female offspring who, in turn, uniparentao due time will abort seven times. These features, as well as other clinical manifestations i.
Van den Berg Loonen. Here, amazingly, UPD 13 has taken place over two generations, once of paternal and once maternal origin, while the other ujiparental 13 has not made its way in the embryonic cells! As a result, recessive traits can be expressed. And, since isochromosomes for acrocentrics have now just been mentioned, let me show, again from literature, some examples of UPD resulting from the presence of two isochromosomes per balanced individual genomes, namely one for each arm of a biarmed chromosome such a number 1, 2 twice4, 7 or 9.
O’Brien and Arthur L. Interestingly enough the journal Science rejected this report, apparently for describing a situation too unipwrental for a broad readership; and, while accepted for publication by the American Journal of Human Genetic, the accompanying editorial almost echoed the very reasons why the other major publications had turned down the article.
From Wikipedia, the free encyclopedia.