The brain gene STX1A plays a significant role in the level of intelligence displayed by patients with Williams Syndrome (WS), a team led by a University of Utah (U of U) USTAR researcher has found.
The study may have implications for the understanding of intelligence and treatment of neurological disease in the general population.
Researchers, led by Dr. Julie R. Korenberg, found that variations in the expression of STX1A could account for 15.6 percent of cognitive variation in a group of 65 WS patients, a very high level of confidence in comparison to prior genetic studies.
STX1A is involved in the electrochemical processes that occur at the brain's synapses.
The study describes a new approach in determining the relationship between gene expression and intelligence in patients with WS- a neurodevelopmental disorder caused by the deletion of only two dozen genes from chromosome 7, a tiny fraction of the almost 30,000 genes found in humans.
"Williams Syndrome patients are missing a very, very small amount of genetic material. In almost all other respects, their make-up is the same as the general population, so we knew to take a very close look at a small number of genes. We analyzed ten different genes, but the data spoke, and STX1A clearly stood out in relation to the different patients' intelligence levels," Korenberg said.
STX1A has a fundamental role in the brain's neurotransmission machinery. It supports the process by which electrical signals speed from one neuron to the next.
"In terms of the brain, we're talking about a basic utility when we look at STX1A," said Korenberg.
The study points the way to further research that may have long-range benefits for WS patients as well as the general population.
Korenberg suggested there may be pharmaceutical treatments in the future that could help enhance synaptic function.
She said that the researchers overcame obstacles with some creative problem solving.
Since brain cells from live patients were unavailable for study, lymphoblastoid cells from the lymph system grown in culture provided the genetic material to analyze.
In addition, the researchers developed a more precise measure of WS intelligence test data, using a technique called Principal Component Analysis (PCA).
In comparison to standardized IQ tests best suited for the general population, the PCA approach was able to better represent a baseline pattern of intelligence in WS patients.
The WS baseline adjusted for relative strengths and weaknesses in the study group, and was able to illuminate the impact of specific genes like STX1A more accurately.
The study was published in the open access/online scientific jounal PLoS ONE.