There is no clear evidence. Some genes may be faulty and so cause certain diseases and conditions which can lead to inherited illnesses. Other differences in our genetic make up can gives us a higher, or lower risk of contracting an illness.
There are a very small number of people world-wide who have a defective gene on chromosome 14 or 21 that seems to trigger Alzheimer’s disease with early onset, often between the ages of 35 and 60 years. It is also known that a protein called Apolipoprotein E, of which we all have a copy of one of three types, affects the our chances of getting Alheimer’s disease. If you have two copies of the E4 version you have an increased risk of Alzheimer’s, the E2 version gives protection against it!
A lot of scientists working in the field of genetics are discovering more and more about our genetic make up giving optimism for an understanding of the genetic mechanisms associated with Alzheimer's. There does appear to be mounting evidence that Alzheimer's disease has a significant genetic component.
This does not mean that because you have a close relative with Alzheimer's that you will get the disease. It just increases your risk factors for it.
