Type 1 dibetes accounts for around 10-15% of diagnosed diabetes, with the estimated increase in Europe being 4% per year (2004). The difference in incidence is vast with the high frequency in finland and Sweden and low frequency in china. It is thought theat the variation in incidence is due to environmental factors in each country and genetic factors in dierent races.
Although it is unknow what exactly triggers the autoimmune reaction, evidence suggests that both genetic predispositions and environmental factors are involved. Genetic factors
Researcher have ound atleast 18 genetic locations, labelled IDDM1-IDDM18, that are related to type 1 diabetes. The genes in this region affect the autoimmune response. Environmental factors
Most people who develop type 1 diabetes don’t have a family history of diabetes. The odds of inheriting the disease are only 10% if a first degree relative has diabetes. Environmental risk factors are thought to act as “initiators” or “accelerators” of the onset of type 1 diabetes. “The type 1 diabetes environmental risk factors that have receive the most attention are viruses and infant nutrition.”(WHO)
Studies of twins have shown that it cant be entirerly genetsics that influence the risk of developing type 1 diabetes. While the concordance rates(the percentage of twin pairs where both twins have the disorder) for monozygous* twins are higher than those for Dizygous twins: approvimatly 30% vs. 10% (Joel Hirschhorn, 2003), most monozygous twins remain discordant. According to the University of Maryland Medical Centre, one monozygous twin only has a 33% chance of developing type 1 diabetes if the other twin does. * monozygous twins are two children who develop from the same zygote(egg) and therefore have exactly the same genetic makeup. If one twin developes diabetes and the other doesn’t then other factors apart from genetics must be important.
There are three major symptoms...