Study IDs 2 Zika Virus Proteins Linked to Microcephaly
Aug 14 2016
Researchers suggest that all babies affected by Zika virus infection inside the womb should be followed and evaluated for bone and muscle problems.
Jung's team discovered that, although the Zika virus contains 10 proteins, only NS4A and NS4B matter when it comes to microcephaly.
In the case of arthrogryposis, the babies have restricted movement in some of their joints and sometimes the joints are stuck in a single position.
Symptoms generally fade after a week, although the Zika virus remains in the bloodstream and can be sexually transmitted, possibly for a few months after it is acquired.
The researchers found the miscreant Zika proteins smack a cellular signaling gatekeeper called "Akt-mTOR pathway" until it is disoriented and can no longer properly guard brain development and autophagy regulation, the cell's recycling factories.
Microcephaly is a birth defect in which a baby's head is smaller than expected when compared to babies of the same sex and age. "After the outbreak of microcephaly in Brazil associated to Zika virus, two studies have suggested an association, but they did not describe in detail the distortions", the researchers said. "Additionally, no children born to mothers who tested positive for Zika have been diagnosed with microcephaly".
A Colorado doctor who performs late-term abortions said it would be inconsistent for people to hold one opinion about abortions for Zika babies, and another about babies with other health problems.
All children showed signs of brain calcification, a condition in which calcium builds up in the brain. One theory is that Zika virus kills brain cells and forms scar-like lesions in the brain on which calcium is deposited, the researchers said.
All the children underwent high definition scanning of the joints and surrounding tissues, but there was no evidence of joint abnormalities.
Microcephaly is the endpoint of the damage, she said.
The outlook for children with arthrogryposis isn't promising, said Dr. Arielle Hay, an attending physician in the division of pediatric rheumatology at Nicklaus Children's Hospital in Miami.
Dr. Amesh Adalja is a clinical assistant professor in the department of critical care medicine at the University of Pittsburgh Medical Center. "Nevertheless, we are trying to develop a cure for that percentage that does get Zika-related microcephaly".
That the association with arthrogryposis doesn't come from the joints but from nerves is not surprising as Zika has proven to have a strong affinity for nerve cells, Adalja said.
Because this is an observational study, no firm conclusions can be drawn about the effect of the Zika virus on arthrogryposis. He's contributed other research on Zika and thinks that this is "a significant development because it pinpoints the molecular players that [cause] the disease in fetus brains, and presumably can provide more precise or novel targets for therapeutics".
Former presidential candidate Marco Rubio, however, told Politico that the fear of Zika complications is no reason to abort a baby.