A large number of complex variants in the human genome, known as "dark matter", which have never been observed before, were recently found by Chinese scientists in Xi'an Jiaoting University in Xi'an, capital of Shaanxi province.

The university announced on Monday that its scientific research team, led by professor Ye Kai, has developed a new analysis process using computer algorithms to analyze and report all types of genome variations from 250 healthy families, including a large number of dark matter that have never been observed before.

There are no two exact same genome sequences, even the genomes of identical twins are formed from the acquired differences in genetic material in the cellular differentiation process. Some differences affect an individual's physical appearance, while others may decide whether they are susceptible to certain diseases.

Ye's team, cooperating with a total of 20 scientific research institutions in the Netherlands, the United States and Germany, identified 1.9 million large genomic variations, in which there was a large fragment of DNA deletion, jumping away and even emerging out of the void.

"These mutations also occur in important functional areas of the genome, such as coding regions that encode key proteins, which can impair the function of the protein," Ye said.

The scientific researchers said that many large genomic structural variants are often not in the coding part of the gene, and some of the functional effects of variation are often difficult to predict.

It was reported that some additional DNA fragments were found outside the protein coding region and had a significant effect on the expression of genes in the vicinity.

"This suggests that even the genomic structural variants that appear outside the coding region need to be closely monitored," Ye said.

The team's study provided a complete set of genomic variants, which enabled the possibility of studying the effects of large genomic structure variations.

In addition, the study also revealed a significant number of large fragments of DNA which had never been observed, and these "extra" DNA could encode protein. For example, a new gene named ZNF was found in half of the Dutch individuals tested.

"Information on this new gene and other dark matter in the genome have been saved to the international database for scientists to study, so as to better understand human diseases," Ye said.

This research result was published in the online journal Nature Communications on Oct 6 and was widely praised in the international bioinformatics research community.