What is penetrance?
Penetrance refers to the likelihood of the condition manifesting in an individual if they carry a faulty copy of the gene. The higher the penetrance, the greater the chance of the condition developing in an individual with a faulty copy of the gene. Most conditions licensed by the HFEA for PGD, are fully penetrant. This means that the condition will inevitably develop in individuals that carry a faulty copy of a gene. For lower penetrance conditions, having a faulty copy of the gene increases the chance of developing the condition compared to the general population, but does not guarantee that the condition will develop.
