New diabetes susceptibility gene identified
Type 1 diabetes or juvenile diabetes is diagnosed in 70,000 children worldwide annually. Genes are progressively being acknowledged as significant in the vulnerability to diabetes. Till date the genetic architecture that triggers the onset of type 1 diabetes has not been obscure. A new study by researchers is set to provide some answers to the elusive questions the genomic mechanisms that underlie susceptibility poses.
Genetic scans, specifically the Genome-wide association studies (GWAS), were employed to seek gene variants frequently observed in people with a certain trait or disease. This study brought out approximately 40 areas of the genome associated type1 diabetes vulnerability. The challenge that the researchers faced was in isolating the genetic variants that essentially cause the disease, due to the diversity of human population.
To overcome this challenge, scientists in Australia used a specific breed of a non-obese diabetic mouse strain to restrict one of 25 genomic areas linked to heightened threat to diabetes to a solitary gene of unidentified function, called AK005651. "We actually got a bit lucky in identifying a mouse gene that hadn't been studied before," said Thomas Brodnicki of St. Vincent's Institute of Medical Research, a senior author of the study.
The researchers, using specific mouse mating, in inbred strains combined bits of DNA between mice, found a piece of DNA encoding the disease-related gene. "In our case, a unique chromosome feature, called a recombination hotspot, stacked the DNA deck in favor of finding this gene," Brodnicki noted.
"This particular hotspot actually changed the identified gene's DNA makeup so that it altered diabetes onset in certain mice," Brodnicki said, outlining the mechanism of DNA sequence variations in AK005651 which eventually linked to decreased production of the gene in the spleen and thymus of diabetic mice.
"Our work does demonstrate that recombination hotspots, which have been relatively neglected in recent genetic studies, should be investigated further for their ability to produce DNA changes in genes that can affect one's risk for developing common polygenic diseases, such as type-1 diabetes." He added.