Genetic counseling is the process by which patients or relatives, at risk of an inherited / genetic disorder / condition, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning in order to prevent, avoid or reduce the risks.
The process of genetic counselling as applied to fetal medicine and prenatal diagnosis is described.
Genetic Counselling is a highly specialised process involves the following steps-
Accurate diagnosis of the genetic condition – This to me is the MOST crucial part of genetic counselling. If the first step is not robust (i.e. the diagnosis of the condition is wrong) all other steps that follow are at risk of being completely off their mark. This is because a clinical condition may have many different underlying genetic possibilities. Indeed, it may not be ‘inheritable’ at all! Many fetal abnormalities seen on ultrasound need to be referred to a fetal medicine expert for this purpose. For example, if only one abnormality is seen in the fetus (isolated) it implies certain things, but if the scan was not conducted by a ‘fetal medicine specialist’, then they may not know what to look for and may miss subtle signs in the fetus. These subtle signs (also called ‘markers’ or ‘soft markers’) may all add up to a completely different diagnosis (syndromic cause rather than sporadic cause of the problem seen on scan).
Understanding of the genetic basis of a condition- Once the diagnosis is made, the fetal medicine specialist will explain the underlying genetics of the condition to you. Many conditions have a variety of genetic possibilities (genetic heterogeneity) and on the other hand, a specific genetic mutation may manifest in various ways ranging from mild to severe (variable expression).