Genetic Counselling - Estimation of Risks

Estimation of Risks of Genetic Counselling

Information on genetic risks is rarely definite and in medical genetics the risks are estimated almost entirely in terms of ‘probabilities or odds’.

Empiric risks

This is the form of risk estimate available for most of the more common non – mendelian or chromosomal disorders. This varies between population and changes with time.

Mendelian risks

These risk estimates can be given only when a clean basis of single gene inheritance can be recognized for a disorder.

This is the most satisfactory form of risk estimate because they allow a clean differentiation into categories of negligible risk.

Mendelian Modes of inheritance:

Example of above type of Autosomal Recessive Inheritance includes the following:

• Cystic Fibrosis
• infantile polycystic kidney disease
• cystinuria
• Zellwegar syndrome