Novel DNA analysis technology improves accuracy of prenatal screening

Prenatal screening for chromosomal disorders gains a significant improvement this week as the DNA analysis technology developed by scientists from the University of Tartu makes the Niptify test more accurate and up to date.

Previously, the Niptify test applied DNA analysis technology transferred and adapted from the Leuven laboratory in Belgium, now the test is entirely based on genetic engineering and informatics solutions developed by Estonian scientists.

The most accurate and earliest prenatal screening test for chromosomal abnormalities is non-invasive prenatal testing (NIPT). It enables the analysis of foetal genetic material extracted from the mother's blood sample using DNA sequencing technology. Foetal DNA is released into the mother's bloodstream as a result of the continuous growth of the placenta. For Estonian families expecting a child, the most available option is the locally developed NIPT test named Niptify, which has so far been detecting the most common chromosomal disorders – Down's syndrome, Edwards' syndrome, Patau's syndrome and Turner's syndromes – with 100% certainty.

Scientists from the University of Tartu and the Competence Centre on Health Technologies (CCHT) developed DNA analysis technology Focus specifically for the Niptify test, which is no longer an adjustment of the scientific method, but addresses the needs of screening.

Kaarel Krjutškov, associate professor in molecular medicine at the University of Tartu and head of the precision medicine laboratory at the CCHT, highlighted that Niptify has undergone deep innovation. "The new technology will help us operate in the field of laboratory medicine securely, economically and in a future-proof way," he says. As a result of the development, the number of laboratory procedures to be carried out on studied DNA has been reduced from 52 to 13, which significantly reduces the time needed for analysis and the amount of disposable plastic labware.

State-of-the-art DNA sequencing technology means that tens of millions of DNA sequences are obtained from a patient's blood sample in the laboratory, which are presented in digital form. Hidden within this data is an encrypted answer to the presence of foetal chromosomal disorders. The data need to be decrypted, meaning analysed, using informatics and statistical methods.

Priit Palta, associate professor at the Institute of Genomics at the University of Tartu and head of the bioinformatics team at the CCHT, explained that the updated software for the Niptify test has been developed specifically to analyse the data obtained using the Focus technology. "The result is a highly accurate yet rapid risk assessment for chromosomal disorders that is ideal for everyday screening," he says.

Palta explained that the goal of bioinformatic development in the current final stage is to identify shorter disease-causing changes or microdeletions with greater accuracy than other commercially available NIPT tests. "This is a very important goal for improving the quality of medical services," he says.

Currently, DNA analysis technology is very advanced worldwide and Krjutškov cannot see any reason why all pregnant Estonian women should not be offered the possibility to do the NIPT test with microdeletion analyses as a part of the national screening programme. "No other country in the world has been able to achieve this, but it would demonstrate the standard of precision medicine and innovation in Estonia. On a nationwide scale, the NIPT screening would cost the Health Insurance Fund two million euros a year. This would make it possible to avoid the huge volume of research currently being carried out and next to money, in addition saving time for patients and doctors," states Krjutškov.

The Competence Centre on Health Technologies is a biotechnology company, whose shareholders include the University of Tartu and the Tartu University Hospital. In 2018, in collaboration with researchers from the University of Tartu and gynaecologists from the Tartu University Hospital and East Tallinn Central Hospital, the company launched the Niptify test, which is currently used in 40 women's clinics all over Estonia and is an integrated part of first trimester screening for pregnant women.

Further information: Kaarel Krjutškov, Associate Professor in Molecular Medicine, University of Tartu and Head of the Precision Medicine Laboratory, Competence Centre on Health Technologies, +372 512 6416, kaarel.krjutshkov@ut.ee