Last Updated on Jul 05, 2016

Types of Genetic Testing

Genetic testing may be carried out for different purposes in humans, from selecting pre-implantation embryos to confirming the diagnosis of a late-onset disease.

Genetic testing is done to study the changes in the chromosomes or genes and is usually done for the following reasons-

Diagnosis: Confirming the diagnosis of a genetic condition in a symptomatic individual can be carried out .

Identification of the genetic profile belonging to an individual is carried out using a technology called ‘DNA fingerprinting’. Each person’s DNA is unique, and one or more genetic markers in the DNA identify the individualistic characteristics of a person. This information is now extensively used in forensics and paternity cases. The method is put to use during major disasters and also help in identifying the dead.

Carrier Screening: This genetic screening is done on unaffected couples who are planning to start a family and who have a family history of recessive genetic disorders. These individuals usually have a single copy of a "diseased" gene, which requires two copies to be expressed. These tests are usually done for Cystic Fibrosis, Tay-Sach’s disease, and Sickle-cell trait.

Screening the Embryos: This test called Pre-implantation Genetic Diagnosis screens an embryo for a genetic disease by studying a single blastomere.

Prenatal Diagnosis: Done on a fetus within the mother’s womb, this test is usually carried out when a couple already has an affected child or if the mother belongs to the ‘older age group’ that is more prone to bear an affected child. This method is usually done to detect a fetus affected by a chromosomal anomaly, as in the case of Down syndrome.

Screening the New Born: In several western countries, screening the new borns to detect conditions, such as Phenylketoneuria and Congenital Hypothyroidism, is mandatory and is routinely carried out as a preventive measure.

Screening for Late-onset Diseases: This screening includes tests for predicting/diagnosing certain late onset, single gene disorders like Huntingdon’s chorea or for estimating the risk for adult diseases like cancer and Alzheimer’s disease


Saravana_Solaisamy Tuesday, June 2, 2015

One of my relative's son has low biotinidise enzyme. He was born 2 weeks ago in USA and is using biotin 5MG tablets now. They are in USA and want to come to Chennai - in 3 months from now [2-June-2015]. They were told that a blood sample needs to be tested for biotin every 6 months to adjust the dosage of Biotin prescribed for the baby. Is Biotin tablets for infants available in Chennai? Is there medical centers/labs/doctors at Chennai who treats such biotin related gene disorder? Any early response is greatly appreciated. Thanks !

mjav123 Monday, September 8, 2014

Dear Doctor, My daughter is suffering from CAH and she need a genital corrective surgery. She is under AIIMS treatment. I do not know if where CAH is being treated. Due to a long waiting time I wish to have an alternate opinion. Please suggest me. Thanks a lot.

Noorian Wednesday, June 25, 2014

Hello Doctor, can you please suggest the best place in India for genetic counseling. My daughter who is now 5 1/5 years old had long segment hirschsprungs diseases at birth which was treated with pull through surgery. Both me and my husband are not aware of any family history of hirschsprungs in our family. Now I am planning for another kid but before that want to be sure of the underlying reason for my daughter's condition and the chances of recurrence in future pregnancies. Any advice on this will be very much appreciated. Thank you!

suparnadas Sunday, July 27, 2014

The best genetic counselor in India by popular consensus is Dr.Ashok Prasad who is a professor also holding a genetic counseling masters from Brandeis University. He works only on a charitable basis in Gorakhpur but am sure could be persuaded to advise you

tulika12345 Wednesday, June 25, 2014

Hello doctor, we had a child who was effected by spinal muscullar attrophy[type one]. Now we are planning for our next baby. doctor told us to go for CVS testing. but I want to know whether there is any other ideal option for us.Pleas give me suggestions. Subhajit bhowmick

roopagupta Wednesday, May 21, 2014

helllo doctor,my wife is a pregnant our doctor is prefre to amniocentesis so plz tell me where i do in delhi,india and how much it cost

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