MedGenome says why more NIPT (non-invasive prenatal testing) is needed in India

Non-invasive prenatal testing can be a boon in prenatal screening.

The incidence of chromosomal disorders in India is 1:166 live births. Given the large population, around 35,000 fetuses with Down syndrome alone are conceived every year. Therefore screening and diagnosis for chromosomal disorders are important in India as in other nations. The current methods for prenatal screening for chromosomal disorders are blood hormone levels and ultrasonography. These methods have low sensitivity and high false positive rate. They hence miss over 10% of an affected fetus. While invasive procedures like amniocentesis and CVS Chorionic villus sampling cannot be offered to all pregnant women as they pose a risk of miscarriage. NIPT on other hand is a screening test that analyses the cell-free DNA of the fetus and gives out a detailed report for any chromosomal abnormalities. The screening is non-invasive, extremely safe and is done by taking a small blood sample from the mother's arm. With detection rate over 99% and a false positive rate at 0.1 % there is a reduction of 50-70% in invasive procedures where NIPT is implemented. The incidence of chromosomal disorders in India is 1:166 live births [1].

Given the large population, around 35,000 fetuses with Down syndrome alone are conceived every year. Therefore screening and diagnosis for chromosomal disorders is important in India as in other nations. The current methods for prenatal screening for chromosomal disorders are blood hormone levels and ultrasonography. These methods have low sensitivity and high false positive rate. They hence miss over 10% of affected fetus. While invasive procedures like amniocentesis and CVS Chorionic villus sampling cannot be offered to all pregnant women as they pose risk of miscarriage. NIPT on other hand is a screening test that analyses the cell free DNA of the fetus and gives out a detailed report for any chromosomal abnormalities. The screening is non-invasive, extremely safe and is done by taking a small blood sample from the mother's arm. With detection rate over 99% and false positive rate at 0.1 % there is a reduction of 50-70% in invasive procedures where NIPT is implemented.

India is a wellspring of untapped genetic knowledge. Its people represent 20 percent of the world's population but only 0.2 percent of the sequenced population. The isolated groups there individually show tremendous similarity within their communities but are extremely distinct from each other. And there are some 4,000 to 5,000 of these groups, or population isolates. Endogamy, the practice of marrying only within a local group, hasn't turned out well in terms of health. Today, many of these isolated populations experience genetic diseases at rates higher than in more genetically mixed communities. Genomic insights are, therefore, substantially easier to discover in India.

To study the feasibility of performing NIPT in Indian population given the above considerations, the study was conducted. The main objective was to evaluate the performance of NIPT for trisomies 21, 18,13, sex chromosome abnormalities and triploidy in a cohort with intermediate to high risk on conventional screening.

• This is the first report of clinical experience with NIPT in India and demonstrates comparable performance in all aspects of testing to the results in the resource-rich countries.
• Ten leading centers participated in the collaborative study Sir Ganga Ram Hospital, New Delhi, Megenome Labs Pvt. Ltd, Bengaluru, Rainbow Hospital, Hyderabad, Amrita Institute of Medical Sciences and Research Center, Kochi, Sri Ramchandra Medical College, Chennai, All India Institute of Medical Sciences, New Delhi, Post graduate institute and Medical Research Center, Chandigarh, Jawaharlal Nehru Institute of Post graduate Medical Education and Research, Pondicherry, CIMAR Fertility Center, Kochi, Manipal Hospital, Bengaluru, Indraprastha Apollo Hospital, New Delhi.
• 516 pregnant women intermediate to high risk on first trimester, Triple marker or quadruple screening were evaluated.

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