Researchers say they now have a better understanding of the causes of the rare genetic disorder Williams Syndrome.
Teams at the Tel Aviv and Hebrew Universities identified that the phenomenon called methylation – when certain molecules prevent genes from expressing themselves properly – disrupts the normal development of the brain’s functions, like regulation of social behavior, and cell survival.
Williams Syndrome causes learning difficulties, a distinctive facial appearance, over-friendliness, and heart and blood vessel problems.
The researchers liken it to tearing out some pages of an instruction book, so that anyone trying to follow the instructions would make mistakes.
The frontal lobe – which is responsible for brain functions like decision-making – was studied among the human brain tissues taken from adults with and without Williams Syndrome.
That said, methylation is in many cases a normal mechanism in the cells of the body. But when it experiences disruptions, it may lead to impairments of cell function and damage to various organs.
Past findings have shown that people with the disease are missing 25 genes from the DNA on chromosome seven. Until now, research has been primarily focused on those missing genes and their functions.
As a result, scientists may be able to develop treatments in the future that will ‘correct’ this cause.
“We uncovered significant information about the defective expression of genes in people with Williams Syndrome, even though these genes are fully present in the genome of the brain cells – until now it was not known that these abnormally-regulated genes are involved in the syndrome,” said Dr. Asaf Marco from the Faculty of Agriculture, Food, and Environment of the Hebrew University.
“In addition, one of our main findings is that the disruptions in methylation do not have to appear near the gene whose function is impaired, and sometimes the disruptions are located at a great distance from it.
“This information is critical because it allows us to better understand the spatial organization of DNA and its effect on gene control. Moreover, since we know of enzymes that are able to remove or add methyl molecules, the next challenge will be to precisely direct those enzymes to the disrupted sites identified in our research, with the aim of allowing the genes to be properly expressed”.