IVF kids show shift in gene activity

Team finds differences related to metabolism and growth

SAN DIEGO — Some genes in children conceived with in vitro fertilization differ in activity levels compared with other children, recent studies show.

 In the most recent work, researchers found substantial differences in activity of dozens of genes of interest, epigenetics researcher Carmen Sapienza of Temple University Medical School in Philadelphia reported February 21 at the annual meeting of the American Association for the Advancement of Science.

With IVF in general, “we’re kind of doing an experiment here,” Sapienza said. “By and large, the kids are fine … but if there are [differences] you can measure, then you should.”

Epidemiological studies have revealed a greater incidence of low birth weight in children conceived with IVF. Among other health issues, low birth weight is a risk factor for obesity, hypertension and type 2 diabetes later in life.

In the Oct. 15 Human Molecular Genetics, Sapienza and his colleagues described differences in one kind of epigenetic mark, DNA methylation, on some 700 genes. The team looked at genes known to play a role in growth, metabolism and other functions of interest. The team showed different methylation levels in 5 to 10 percent of the genes investigated in a group of children conceived via IVF compared with children conceived naturally.

Sapienza examined levels of RNA to gauge gene activity and determined that the differences in DNA methylation patterns did translate to differences in activity for some of the genes identified in the earlier study. Several of those genes are known to play a role in fat cell development or insulin signaling.

About 90 percent of the children in the IVF group were still within the normal range of gene activity levels, Sapienza said.

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