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What is
Preimplantation Genetic Diagnose (PGD) : |
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Many of couples have genetic
disorder, and they have high
risk of transmitting the genetic
disorder to their offspring.
Since now there was no technique
to detect the same prior to the
pregnancy being achieved.
Preimplantation Genetic Diagnose
(PGD) is new hope to detect the
genetic disorder.
Preimplantation genetic testing
is a technique used to identify
genetic defects in embryos
created through in vitro
fertilization (IVF) before
pregnancy. Preimplantation
genetic diagnosis (PGD) refers
specifically to when one or both
genetic parents has a known
genetic abnormality and testing
is performed on an embryo to see
if it also carries a genetic
abnormality. In contrast,
preimplantation genetic
screening (PGS) refers to
techniques where embryos from
presumed chromosomally normal
genetic parents are screened for
aneuploidy.
Because only unaffected embryos
are transferred to the uterus
for implantation,
preimplantation genetic testing
provides an alternative to
current post conception
diagnostic procedures (ie,
amniocentesis or chorionic
villus sampling), which are
frequently followed by the
difficult decision of pregnancy
termination if results are
unfavorable. PGD and PGS are
presently the only options
available for avoiding a high
risk of having a child affected
with a genetic disease. It is an
attractive means of preventing
heritable genetic disease before
implantation, thereby
eliminating the dilemma of
pregnancy termination following
un-favorable prenatal diagnosis.
Primary candidates for PGD
include the following:
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Couples with a family history
of X-linked disorders (Couples
with a family history of
X-linked disease have a 25%
risk of having an affected
embryo [half of male
embryos].)
-
Couples with chromosome
translocations, which can
cause implantation failure,
recurrent pregnancy loss, or
mental or physical problems in
offspring
-
Carriers of autosomal
recessive diseases (For
carriers of autosomal
recessive diseases, the risk
an embryo may be affected is
25%.)
-
Carriers of autosomal dominant
diseases (For carriers of
autosomal dominant disease,
the risk an embryo may be
affected is 50%.)
More on PGD |
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