Wednesday, 1 January 2020

Male chromosome defect may be the cause of Recurrent abortion: Microdeletion


  Y  micro deletions  ::Do you believe if I say that couples suffering RPL 32.5% of males were carriers of chromosome Y  micro deletions  and after excluding  the female  factor  in 13. 5%   of the cases. Y Micro deletions : Do U honestly believe that there is a link between RPL and male   carriers of   Y  chromosome    deletions ??  What is your view??

What is meant by azoospermia factor    ?    Molecular   genetics of severe   male infertility, % of the oligo azoospermia males. Can    Y  chromosome    deletions  may lead to  RPL that in couples suffering RPL 32.5% of males were carriers of chromosome Y  micro deletions  and after excluding  the female  factor  in 13. 5%   of the cases .
Male Carriers of Chromosome Y Micro deletions
Severe   male infertility: can it be  due to micro deletions of the chromosome of Y long arm?? Ans: Yes.  It is quite possible. Microdeletion of Y arm of a male are the most frequent abnormal molecular   genetics of severe   male infertility . Such are  mainly exhibited    by the presence of   severe oligozoospermia and non obstructive azoospermia  Nowadays   these genetic    alterations could be screened   as routine   which is important since  they are present  in approximately in 9% of the oligo azoospermia males(OAT) .
At the molecular   level   Y chromosome microdeletions affect at least three regions known   as azoospermia factor     regions. All these three regions of Y chromosome are important in sperm production. Therefore to sumarize these three regions  are essential   for a   successful spermatogenesis. Different   micro deletions have deleterious effects  in different  aspects   of male fertility . It is of note though   the AFZ cv 2/64   deletions since men carrying   them produce    a higher percentage   of nullisomy for the sex    chromosome   and NY   disomy  . There is a link between male   carriers of   Y  chromosome    deletions and RPL   was suggested  . It has been observed that in couples  with RPL  a significant percentage   of the  males   had chromosome Y  micro deletions . Another   study   carried out by Agarwal et al in 2015   stated that in couples suffering RPL 32.5% of males were carriers of chromosome Y  micro deletions  and after excluding  the female  factor  in 13. 5%   of the cases. Interestingly the most  frequent   micro deletion was the AZFc The incidence of    chromosome Y   micro deletion   is different in different  population    since is linked  to chromosome  Y  haplogroups  .But another study carried out at Delhi by  venkatesh et al   did not  detect   any micro deletion  in a population of RPL  in New Delhi.
Nevertheless taking  in account  the population  that we are  working  with  this novel data    suggests   that micro deletions in chromosome Y   could be the cause  of RPL  so the study    of these   chromosomal   abnormalities   could be offered to couples with idiopathic abortion .
De novo  Duplications / Deletions from Couples with Normal  Karyotype
Sporadic early  pregnancy loss    occurs  in   10-15%  clinically recognized  gestations. As  we have  mentioned   earlier  must of the cases of miscarriages are    due to full chromosomal   trisomies  or monosomies. Nevertheless  in some cases   the  cause of these   abortions could be submicroscopic  chromosomal changes like    duplications and / or   deletions  . The problems is that these structural  abnormalities  could  appear    de novo. This    mens that even though   parents   have a perfectly normal karyotype the embryos could carry   a dup/ del. In these cases the recurrence  risk would be  similar   to general    population  With   the introduction  by pre implantations genetic  testing  for aneuploidies for aneuploidy   screening   also in couples  with normal    karyotype  small dup /del   have been  indentified   in per implantation   embryos  also/ The introduction  of more accurate  techniques like array comparative genomic hybridization and Next   Generation seque3ncing enable the clinicians   the possibility  of  detecting   these small changes in the embryo  before    transfer   in IVF   couples



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