The breakthrough could help identify those who may be susceptible to the condition and could lead to new drug treatments that target the genetic faults.
Twelve new genes were identified by the international consortium led by Professor Mark McCarthy of the University of Oxford after looking at thousands of sufferers and non-sufferers.
The identification of the new genes brings the total number of genetic regions known to be associated with type 2 diabetes to 38.
The genes are involved in the working of pancreatic cells that produce and control the hormone insulin, which is crucial for controlling levels of glucose in the blood.
The findings not only improve understanding of the processes underpinning type 2 diabetes, but give new biological pathways that can be explored as targets for new therapies.
"Gradually we are piecing together clues about why some people get diabetes and others don't, with the potential for developing better treatments and preventing onset of diabetes in the future,’ said Professor McCarthy.
Type 2 diabetes represents one of the most significant global threats to health.
There are around 2.5m people in Britain with diabetes, including the inherited type 1 which is not linked to obesity, and about 500,000 people do not know they have the condition.
The consortium of researchers – from across the UK, Europe, USA and Canada – compared the DNA of over 8,000 people with type 2 diabetes with almost 40,000 people without the condition at almost 2.5 million locations across the genome.
They then checked the genetic variations they found in another group including over 34,000 people with diabetes and almost 60,000 controls.
Although the study found 12 new genetic regions where the presence of a particular variation in DNA sequence leads to an increased susceptibility to type 2 diabetes, the individual effects are small.
That is, possessing one of these gene variants leads to only a marginal, but clear, increase in the risk of developing the condition
However, the potential impact of the findings in terms of new biology and possible therapeutic developments could be significant.
Dr Iain Frame, Director of Research at Diabetes UK, said: “This is strong research and adds to our knowledge of the genes that increase the risk of developing Type 2 diabetes.
"As we continue to add more pieces to the jigsaw, our greater understanding of the genetics behind Type 2 diabetes could lead to new avenues of research into prevention and improving treatments.
“It is important to remember that Type 2 diabetes is strongly linked to being overweight or obese.
"If we can tackle obesity then we can make real inroads to fighting Type 2 diabetes and reducing the number of people develop
The findings are reported in the journal Nature Genetics.
