What Is Pre-implantation Genetic Testing?
By
Alfred Akuki
How is the PGD performed?
Pre-implantation genetic diagnosis begins with the
normal process of in vitro fertilization that includes egg retrieval and
fertilization in a laboratory. Over the next three days the embryo will divide
into eight cells.
Preimplantation genetic diagnosis involves the
following steps:
• First,
one or two cells are removed from the embryo.
• The
cells are then evaluated to determine if the inheritance of a problematic gene
is present in the embryo.
• Once
the PGD procedure has been performed and embryos free of genetic problems have
been identified, the embryo will be placed back in the uterus, and implantation
will be attempted.
• Any
additional embryos that are free of genetic problems may be frozen for later
use while embryos with the problematic gene are destroyed.
Who might benefit from PGD?
Preimplantation genetic diagnosis can benefit any
couple at risk for passing on a genetic disease or condition.
The following is a list of the type of individuals
who are possible candidates for PGD:
• Carriers
of sex-linked genetic disorders
• Carriers
of single gene disorders
• Those
with chromosomal disorders
• Women
age 35 and over
• Women
experiencing recurring pregnancy loss
• Women
with more than one failed fertility treatment
PGD has also been used for the purpose of gender
selection. However, discarding embryos based only on gender considerations is
an ethical concern for many people.
What are the benefits of PGD?
The following are considered benefits of PGD:
• PGD
can test for more than 100 different genetic conditions.
• The
procedure is performed before implantation thus allowing the couple to decide
if they wish to continue with the pregnancy.
• The
procedure enables couples to pursue biological children who might not have done
so otherwise.
Human eggs are often chromosomally abnormal – and
the percentage of eggs with a chromosomal abnormality increases with increasing
female age. In general, about 30 to 60 per cent of human embryos have some type
of chromosomal abnormality. This increases significantly with advancing female age.
Comments
Post a Comment