Heredity and Disease

It is generally known that diseases can be inherited. The nature of inheritance usually follows the well known Mendel’s laws of inheritance. Such diseases like diabetes, asthma, mental deficiency, hemophilia (bleeding disease), colour blindness, etc., are all examples of hereditary diseases. But perhaps what is widely not known is the fact that hereditary factors play a role in practically all diseases. The contribution of heredity may not be apparent but what can be termed as a predisposition or proclivity is always determined by heredity. It should be appreciated that a biological being is the product of inherited genes (genotype) and the effect of environment. Therefore, the contribution of genotype is always there whether in disease or health. There are still many diseases for which apparently no cause is yet known. This should not be surprising in view of the fact that innumerable factors can be casually connected with the disease and there are obvious difficulties in evaluating them by methods available to medical science today.