Hyderabad: DNA sequencing has proved to be a boon for families planning children but have a recurrent history of abortions or stillborns. It also helps them to know if the foetus suffers from one or the other genetic disorders.
The technology was earlier used for paternity tests to ascertain the identity of the dead especially in criminal cases by matching genetic samples with those of their families.
It was discovered only recently that sequencing of the DNA could help identify the health of the foetus. While embryo technology makes it easy to look into the manner in which cells are dividing and identify the healthy eggs, DNA sequencing helps spot genetic disorders which are not otherwise visible.
Down's Syndrome, haemophilia and muscular dystrophy are some of the common genetic disorders seen in children here. In the case of Down's Syndrome, experts say ultrasound scans do not show if the organs are not developing properly.
For this reason, genetic testing is recommended for couples marrying within the same family.
Dr Suma Hari Prasad, senior gynaecologist, said, "DNA sequencing is required when there are recurrent miscarriages. In these cases, it is found that 70 per cent of the embryos have chromosomal abnormalities and 15 per cent of patients have all embryos that are chromosomally abnormal. Advanced maternal age is also one of the reasons for these abnormalities."
The increase in the number of genetic disorders, genomic complexity and low sensitivity has made it important to ensure that proper screening is carried out. DNA sequencing helps identify single gene disorders and chromosomal anomalies which are responsible for embryo abnormality.
Dr Prasad said, "We get this information decoded by bio-information technology experts who give us inputs on what types of chromosomes are defective. It helps in selection of the right embryos and ensure that IVF implantation is done successfully with healthy eggs."
Dr G.V. Rao, forensic science expert, said genetic testing gives evidence of the diseases prevalent in the genes like muscular dystrophy, Down's Syndrome and cystic fibrosis.
"Genetic testing gives a variant of 25 diseases. If found, it is decoded and explained to the expectant mother's family."
But what is most important is the acceptability and will power of the patient to understand that they could be passing on a genetic defect. This requires skilful presentation of the problem. Doctors present videos and pictures of these tests so that couples get a clear idea of the problem.
