A concerned Texas mom finally has answers about the cause of her son’s sensory-processing problems, thanks to a special collaboration among her patient-advocacy group and the lab of Scripps Research Neuroscientist Gavin Rumbaugh, PhD.
Monica Weldon of Cypress, Texas, says her son Beckett, a 10-year-old fraternal twin, has never experienced pain the way his sister, or other children, do.
“His pain threshold was so high,” Weldon says.
While he had signs of autism, he had other symptoms that were not typical.
“He walked around with a broken finger for four days and we didn’t know it was broken.”
Beckett has a genetic mutation that results in deactivation of a gene called SYNGAP1, which is critical to healthy brain development. Rumbaugh’s research, published in the journal Nature Neuroscience, for the first time links disordered touch and pain processing to SYNGAP1 mutations. Rumbaugh and his co-authors note that children born with only one working copy of the gene are known to exhibit a wide range of symptoms, including autistic traits, epilepsy, and intellectual disability. Analysis of a patient registry that Weldon helped assemble, plus a series of experiments in an animal model of the condition, led to the discoveries.
“We knew SYNGAP1 was critically important for synapse plasticity,” a term for experience-driven changes in neural circuitry, says Rumbaugh, the study’s senior and corresponding author. “What we found is in addition to that, it also seems to regulate how many connections are made in the brain’s primary somatosensory cortex, in how we process touch-related sensory information. That was a surprising finding.”
It was surprising, in part, because previous research showed that SYNGAP1 mutations cause hyper-sensitivity in the other senses. The processing of hearing and sight may be on overdrive, and yet the researchers found that touch awareness and pain sensation barely register in somatosensory circuits.
SYNGAP1 mutations are rare, but recent studies have estimated that tens of thousands of individuals globally may live with them, Rumbaugh says. Families learn of their child’s SYNGAP1 status only after pediatricians notice missed milestones and then order genetic tests, he adds.
Thanks to the internet and Bridge the Gap, families are finding each other and sharing such vital information. The new findings show how powerful these connections can become when families partner with scientists like those at Scripps Research, Weldon adds.
“This open communication is getting us closer to understanding what this gene really does and possibly developing precision medicine approaches for treating these kids.”
The next step in Rumbaugh’s research is to look at treating the symptoms from the genetic mutation.
Scripps Research Press Release can be found here.
