Medical Science has witnessed huge progress in the last few decades. The unprecedented technological growth has enabled the introduction of many new and sophisticated medical procedures and tools. Genetic testing is one such procedure which is carried out to ascertain the status of the genes in an offspring.
A sample of blood or any body tissue is taken to discover and learn the changes in the genes and chromosomes. This procedure is helpful especially in cases where they parents want to know if the fetus is carrying genes of any inherited or transmitted disorders.
Changes in the genetic codes can lead to quite a lot of diseases. Gene mutation or alteration can affect the ability of a gene to create protein or can lead to creation of different proteins. Such abnormality can lead to the occurrence of some diseases in the body as it affects the normal functioning of the body. Gene mutations occur as a result of inheritance of genes by birth in a particular family or ethnicity, abnormalities in chromosome pairs, etc.
A gene is basically a sub-unit of DNA. DNA or Deoxyribonucleic acid consists of two spiral strands. The two chromosome pair present in the DNA carries genes. One pair of chromosome is inherited from the father and the other from the mother. DNA is present in each cell in the body and provides the genetic information. It is responsible for producing proteins that enable the cell to function in a proper manner.
Furthermore genes have variants, namely dominant allele and recessive allele and as the name suggests, the dominant allele succeeds over the recessive allele. A person carrying a recessive allele acts as a carrier for the disease and does not suffer from the disease himself. But if a recessive gene is transmitted into an offspring from both the parents, there is a probability that the offspring will develop the disease.
Genetic Testing: Is it Safe or Not?
Usually doctors advise parents to carry out a genetic test on the offspring to ascertain if the offspring carries altered genes and to decipher the probability of passing the gene to the offspring. This test is highly advisable for parents with a family history of inherited diseases. An offspring with the presence of an altered gene in his system might not catch the disease. However this disease can be transmitted to the offspring’s children.
Parents of children born with congenital defects are also advised to carry out genetic test to determine the reason for the abnormality. Birth defects can occur due to other reasons besides altered genes. Traumatic incidents during the course of the pregnancy, exposure to harmful radiations or presence of an infection can also cause birth defects. The occurrence of an error in the gene of the offspring can also be a reason for congenital defects. Genetic testing is also recommended in cases of frequent miscarriages.
It helps to identify the chromosomal problems present in the fetus and determine the existence of birth defects. Giving birth to a still born can also be attributed to genetic disorders which cause physical abnormalities in the baby making it difficult for the offspring to survive. Genetic abnormalities can lead to certain distinctive physical characteristics in a new born.
Women who conceive in their middle thirties suffer a huge risk of giving birth to a baby with chromosomal abnormalities. Trisomy is one of the abnormalities found in offspring who are conceived by the mother after an age of 34 years. Men who become fathers in their old age too run a chance of having a baby with genetic mutations. Genetic testing aids parents in determining the probability of their child inheriting a certain disease and accordingly plan a diagnosis for it. This test is quite useful for aspects such as career and family planning, etc.
Conducting Genetic Testing during Pregnancy
In order to conduct genetic testing during pregnancy, two options are available, namely aminocentesis and chorionic villus sampling. Aminocentesis can be performed between 16-18 weeks of a pregnancy. A hollow needle is carefully inserted into the pregnant woman’s abdomen. The needle is used to take out little amount of amniotic fluid which surrounds the developing fetus. The sample of the fluid is then passed through procedures to determine the existence of genetic mutations and to ascertain the sex of the baby. In cases where the delivery might have to be done through caesarean or there are chances of premature delivery, this test allows the doctors to know the development of the fetus’s lungs. However there is a shortcoming of this test.
At times, it can induce a miscarriage of the fetus. Chorionic villus sampling is carried out between 10-12th week of a woman’s pregnancy. A tiny piece of the placenta cord is detached to check for the existence of altered genes in the fetus. This test is comparatively safer as compared to aminocentesis as the risk of inducing a miscarriage is greatly reduced in this test.
The Benefits and Shortcomings of Genetic Testing
Genetic testing allows parents to abort fetus carrying genetic mutations to such an extent that it can lead to severe abnormalities in the child. It is a safe way to determine the existence of terminal diseases in a fetus and treat them at the right stage to avoid complications in the future. Diagnosing the presence of certain conditions in a child can help parents to take preemptive steps to ensure a healthy life for their child. Nonetheless, genetic testing can only predict the presence or alternatively, the absence of alerted genes. It cannot accurately predict if the offspring will suffer from the inherited disease or not.
Moreover the interpretation of the results of the test is subjected to the knowledge and experience of the physician conducting the tests. The chances of an error during conducting the test in the laboratory is another drawback associated with genetic testing which can give inaccurate results. Genetic testing has a huge impact on the decision regarding the life of the offspring. Any mistake can lead to irrevocable damages for the offspring. Hence it needs to be carried out in the best interest of mankind and with utmost care.