Scientists say a gene variation could contribute up to 155g to a child’s birth weight.
The gene studied is believed to act as a growth suppressor, reducing birth weight. But UK-based researchers found that a particular variant passed down from the mother can add 93g to birth weight, or 155g if passed down from the maternal grandmother.
Professor Gudrun Moore of University College London and his colleagues looked at a gene called PHLDA2 in nearly 9,500 DNA samples taken from mothers and their babies, collected in three separate studies.
They found that a gene variant called RS1 appeared to change the way in which the gene functioned, leading to higher birth weights. “The gene is already known to have a profound effect on birth weight by acting as a growth suppressor,” Moore said.
The RS1 variation was found in around 13 percent of the individuals studied, with 87 percent possessing the RS2 variation. “We suggest that the more common RS2 gene variation, which is only found in humans, has evolved to produce a smaller baby as a protective effect to enhance the mother’s survival during childbirth,” said Moore.
1. variant n.
變異；變化版 (bian4 yi4; bian4 hua4 ban3)
例: There are many cola flavors on the market now, which are all variants of the original one.
2. pass down v. phr.
流傳，傳承 (liu2 chuan2; chuan2 cheng2)
例: His occupation is a family trade, passed down from generation to generation.
3. maternal adj.
母系的；母性的 (mu3 xi4 de5; mu3 xing4 de5)
例: She is very maternal towards her staff.