Why are you more likely to get type one diabetes if someone in your family has type one diabetes? Is it genetics or

Question: Why are you more likely to get type one diabetes if someone in your family has type one diabetes? Is it genetics or their actions?
- Keywords:
  disease,
  gene
Asked by u12tsangv to Simon on 19 Nov 2013.
- Simon Langley-Evans answered on 19 Nov 2013:
  
  Type 1 diabetes has a genetic element to it, but we don’t consider it to be an inherited disease. Most people have a risk of about 1 in 300 of developing type 1 diabetes and it usually appears in childhood. If a person has a parent or brother or sister with type 1 diabetes, their risk is 6 in 100, so nearly 20 times greater. Lots of different genes have been identified that might be linked to type 1 diabetes.The reason people develop it is because their own immune system attacks their pancreas and destroys the cells which make insulin. Genetics may explain why the immune system misbehaves in that way.
  
  Tyoe 2 diabetes also has some genetic influences, but is also greatly influenced by lifestyle. Being overweight is the biggest risk.

Question: Why are you more likely to get type one diabetes if someone in your family has type one diabetes? Is it genetics or their actions?