What Genetic Syndromes Tell Us
What does the repertoire of human mutations as manifested in inherited disease tell us?
It tells us about the genetic makeup of man. The list of X-linked genetic diseases, for example, tells us about the genetic constitution of the X chromosome. It can be likened to a photographic negative from which a positive picture of the genetic constitution of the X chromosome can be derived.
Why are there so few categories of commonly observed genetic syndromes?
There are only so many ways the human body can respond to an exogenous agent such as an infectious organism, or an internal agent, such as a mutation. There is only so much phenotypic variation that is possible. For example, even though an effort has been made to relate each of the entries in my book (Mendelian Inheritance in Man) on all confirmed genetic disease
McKusick VA. Diseases of the Genome. JAMA. 1984;252(8):1041-1048. doi:10.1001/jama.1984.03350080043025