|Genetic Counselling & Prenatal Diagnosis of Genetic Disorders|
A doctor may recommend genetic counselling and testing for a mother-to-be if there is a concern that a baby may have a genetic abnormality.
caused by these abnormalities are rare, accounting for only
about 3% of all births. And about 95% of prenatal tests are negative,
indicating no identifiable foetal abnormalities. Detecting an abnormality
before delivery allows time to consider an or prepare for
a baby who may have special needs.
You may be concerned about your baby's
if you or your partner has a in the family, if you already have a child with an inherited
disorder or birth defect, or if you are in your late 30s or 40s. Genetic
testing may also be advised if you and your mate are blood relatives,
such as first cousins, or if either of you has been exposed to radiation,
medication, chemicals, or infection that may pose a risk to the foetus.
Tests such as , , and are now available for detecting hundreds of genetic diseases, including
cystic fibrosis, Tay-Sachs disease, sickle-cell anaemia, beta thalassemia,
Gaucher disease, Huntington disease, haemophilia, Duchenne muscular dystrophy,
Of course, most of these disorders are rare.
particular test may be ordered only when the disorder is severe and there
is a significant risk that the baby carries the genes for this disease.
Thus, the risk of occurring in babies born to women under
age 35 is not sufficiently high to warrant amniocentesis, a test that
itself carries certain risks. Genetic tests may be performed on future
parents to check whether they carry recessive, or hidden, genes for a
disease. Generally, there is a risk to the baby only if both parents are
found to be carriers of the abnormal gene. Tests involving the foetus may
consist of evaluating the foetal chromosomes, measuring enzymes or other
products produced by genes, or evaluating the genes themselves.
If a suspected disorder affects only babies of one sex, determining the
gender of the foetus may serve as an initial screening method.
The information in this page is presented in summarised form and has been taken
from the following source(s):
Hygeia Foundation : http://hygeia.org/
(def;articles & more)