Han Chinese share gene characteristics with Indians and Europeans, study finds

A large-scale gene sequencing project that collected DNA samples from pregnant Chinese women revealed links to birth outcome and babies’ disease risk

PUBLISHED : Saturday, 06 October, 2018, 11:47am
UPDATED : Saturday, 06 October, 2018, 10:39pm

The Han Chinese and ethnic minorities share some common gene mutations with Indians, Southeast Asians and Europeans along the Silk Road, an unprecedented study of DNA samples has found.

In the largest genome sequencing of the Chinese, a group of international scientists studied the gene sets of about 140,000 women in China, uncovering relations between genes and birth outcomes such as the delivery of twins and babies’ risks of certain infectious diseases.

Researchers assembled a representative sample of the entire Chinese population, according to the study, published on Thursday in the journal Cell.

Further analysis of the genomes could reveal valuable information about migration patterns and disease risks in Chinese populations, it said.

The large-scale gene sequencing project was made possible by a technique called non-invasive prenatal testing (NIFT), which requires only a blood sample taken from a pregnant woman, the study said. The procedure has been adopted by millions of expectant mothers around the world to check the fetus’ risk of certain genetic diseases.

“It has been administered to about 6 to 7 million Chinese women and an estimated 10 million women worldwide,” said Liu Siyang, a co-author of the study and a researcher with BGI, a Chinese biotech company.

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The novel technique has lowered the cost of DNA sequencing in a group large enough to study the genetic make-up of China’s 1.4 billion population, said Xu Xun, also a co-author of the study and a researcher with BGI in Shenzhen. It also helped researchers gather a sample as large as 141,431 people, as the testing is widely provided in 34 administrative provinces in China.

“Although the prenatal testing is low-pass sequencing, meaning it only captures about 6 to 10 per cent of the whole genome randomly, there’s still a chance that using this data with a large population size will help us to see what the Chinese genetic population looks like,” Xu said. “NIFT is such a unique opportunity for us to access a large population size.”

The participants come from 31 out of 34 provinces in China and comprise 36 of the nation’s 55 ethnic minority groups, the study said.

“Our participants represent one in 10,000 of the Chinese population, so it really is large sampling and a good reflection of the entire population,” says Jin Xin, another co-author of the study and a researcher with BGI and South China University of Technology.

Analysis of the DNA samples also found that mutations of a gene called NRG1 are related to the formation of identical twins, as well as genes that could cause newborns to contract roseola, or rose rash.

“It’s amazing that this is even possible – that you can take these massive samples and do association mapping to see what the genetic variants are that explain human traits,” said co-author Rasmus Nielsen, a professor of integrative biology at the University of California, Berkeley, who oversaw the computational analysis performed by researchers at BGI in Shenzhen.

BGI said it has obtained informed consent from each participating woman to analyse the sequenced genomes, maintaining anonymity. The data is hosted in the China National GeneBank, the study said.