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Link Found Between Low Birth Weight And DNA From Mothers

Date:
April 25, 2002
Source:
University Of Washington
Summary:
Using a unique set of data collected over 30 years and six generations of captive-bred monkeys, researchers have found the first evidence that low birth weight is linked to a type of DNA only passed along by females.
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Using a unique set of data collected over 30 years and six generations of captive-bred monkeys, researchers have found the first evidence that low birth weight is linked to a type of DNA only passed along by females.

"This is why, when it comes to birth weight, we tend to be more like our mother than our father," said James Ha, a University of Washington research professor of psychology and lead author of a study published in the current issue of the American Journal of Primatology. The National Institutes of Health funded the research.

"We definitely think that our findings will hold up when human data becomes available," he said. "Some people have suggested that birth weight in a number of species including humans is closer to the mother than the father. But there never has been adequate data to test a hypothesis of cytoplasmic DNA inheritance. Instead, human research has focused on environmental causes."

While the new study links maternal genetics to low birth weight, it does not mean pregnant women should ignore known environmental risk factors such as alcohol, drugs and a poor diet that contribute to the birth of underweight babies. Ha said that there is more than one type of DNA, or deoxyribonucleic acid, the material in cells that carries the genetic code and transmits hereditary traits.

"People tend to look at DNA as only being inside the nucleus of a cell. However, there also is DNA in the cytoplasm that surrounds the nucleus inside the cell membrane. Some of this DNA is found in mitochondria."

Mitochondria are structures that are the so-called "powerhouses" that control energy production in cells and mitochondrial inheritance is only passed along to offspring by the mother. He said the connection between how much energy is produced and low birth weight "makes so much sense."

Ha calculated that cytoplasmic DNA from mitochondria is responsible for 9 percent of the variability in birth weight, while traditional nuclear DNA accounted for an additional 42 percent of the variability. This suggests there may be a gene or genes that control birth weight.

"The next step is to find which gene or genes are responsible and what pathway controls this process. We also need to look for links between genetic effects of low birth weight and other factors that endanger children such as low IQ," he said.

"We want to know why birth weight is a risk factor for other perhaps more critical things. One possibility is that there is a gene that affects birth weight, and the same gene controls IQ, retardation and memory difficulties. That gene has two effects, but we don't know if there is a direct or indirect connection. We believe there may be a genetic component in common, and if we can identify the genes and the mechanism we then can explore why children are at risk."

The study is based


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Materials provided by University Of Washington. Note: Content may be edited for style and length.


Cite This Page:

University Of Washington. "Link Found Between Low Birth Weight And DNA From Mothers." ScienceDaily. ScienceDaily, 25 April 2002. <www.sciencedaily.com/releases/2002/04/020425072417.htm>.
University Of Washington. (2002, April 25). Link Found Between Low Birth Weight And DNA From Mothers. ScienceDaily. Retrieved March 27, 2024 from www.sciencedaily.com/releases/2002/04/020425072417.htm
University Of Washington. "Link Found Between Low Birth Weight And DNA From Mothers." ScienceDaily. www.sciencedaily.com/releases/2002/04/020425072417.htm (accessed March 27, 2024).

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