FEB 03, 2018 3:30 PM PST

Genetic Factors Make Babies Susceptible to Zika

WRITTEN BY: Carmen Leitch

Zika virus can lead to devastating birth defects in babies born to infected mothers, but only about six to twelve percent of children potentially affected by the disease end up having those problems. Scientists have long suspected that there are factors other than the virus at work when it comes to such congenital defects. A new study reported in Nature Communications has indicated that susceptibility to the disease has genetic roots.

Mosquitos carry the Zika virus. / Image credit: Freestockphotos.biz

"We studied pairs of discordant twins - cases in which only one twin was affected by the virus, although both had been equally exposed during pregnancy. In the laboratory, we found some 60 genes with differentiated expression in the neural progenitor cells of the affected babies," explained one author, Mayana Zatz, a professor at the University of São Paulo's Bioscience Institute (IB-USP).

The symptoms seen in the affected children include brain calcification, microcephaly, and auditory and visual problems.

Scientists gathered data on 91 babies that had infected mothers, which included several sets of twins. In all monozygotic twins, who split from the same fertilized egg, both individuals were equally affected. In dizygotic pairs, who originate from different eggs, only one of the twins was impacted.

Additional biological samples were obtained from dizygotic twins, and a team at the Human Genome & Stem Cell Research Centre (HUG-CELL) team created a way to make induced pluripotent stem cells ( iPSCs) from the patient's blood cells. Then they made neural progenitor cells (NPCs) from the iPSCs. NPCs are the cells that suffer the biggest impact from the pathogen. Once these cells were growing in culture, they were infected with Zika virus.

"From the start, we were struck by the fact that the virus replicated much faster in the NPCs from the affected babies," Zatz said. "In addition, these cells proliferated less and died more than cells from unaffected babies. We appear to have succeeded in reproducing in vitro what happens in vivo."

The team then looked for differences in gene expression in these cultured NPCs, finding several that are key to brain development. Two cell signaling pathways were identified, one controlled by mTOR and the other by Wnt.

"These pathways regulate the proliferation and migration of central nervous system cells, among other things," Zatz explained. "The expression of several genes linked to these pathways was reduced in the NPCs from affected babies. One was 12.6 times less expressed in affected cells than the same gene in cells from the unaffected twin."

Similar results were found in all three sets of identical twins, reinforcing the hypothesis that genetic factors influence the effects of the virus.

Zatz added that this work and other studies supporting this idea might help to identify parents who are most at risk of having affected babies. "If and when a vaccine against Zika is developed, these parents could be prioritized in immunization strategies," she said.

The video above from the American Academy of Pediatrics outlines why pregnant women should avoid traveling to areas impacted by the Zika virus.

Sources: AAAS/Eurekalert! Via FAPESP, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAR 23, 2020
Genetics & Genomics
MAR 23, 2020
Diagnosing Cancer by Looking for Microbial DNA in the Blood
Liquid biopsies aim to diagnose a disease with only a bit of biological fluid, usually blood.
MAR 24, 2020
Cell & Molecular Biology
MAR 24, 2020
Certain Drugs May Raise the Risk of a Severe COVID-19 Infection
ACEIs and ARBs may make coronavirus infections worse, which can help explain why older adults are faring so much worse.
MAR 26, 2020
Cell & Molecular Biology
MAR 26, 2020
A Large Cavity is Discovered in a Tuberculosis Protein
Scientists have discovered something very unusual about a protein that is thought to be important to the development of ...
APR 01, 2020
Microbiology
APR 01, 2020
How Two Types of Tests for COVID-19 Work
There are a couple of different kinds of tests that researchers will be developing and clinicians will be using to disru ...
APR 29, 2020
Microbiology
APR 29, 2020
Bacteria Exposed to Antibiotics are 'Primed' to Gain More Resistance
Antibiotics are critical drugs that have saved millions of lives, but bacteria can also gain resistance to them, renderi ...
MAY 24, 2020
Microbiology
MAY 24, 2020
Cavity-Causing Microbes Are Protected by Rings of Sugars and Germs
Bacteria can form tough communities called biofilms, which are difficult to remove and can resist the effects of antimic ...
Loading Comments...