Genetic counselling helps individuals and families affected by or at risk of genetic disorders to understand and adapt to the disease.
The genetic counsellor will collect a patient’s personal and family health history and use this information to determine how likely it is that they, or a family member, has a genetic condition. Depending on the particular situation, the genetic counsellor may recommend a genetic test be conducted.
Reasons for genetic counselling:
- If a doctor has observed symptoms that may indicate a genetic disease (cardiac, neurodegenerative, metabolic, etc).
- If there exist instances of hereditary disease in the family: hereditary cancer, congenital malformations or chromosomal alterations.
- If more than 2 close relatives in the family suffer or have suffered from the same disease.
- If a patient suffers from infertility, or they have had two or more miscarriages, or their baby was stillborn.
- If a couple is related and are considering having children.
- If a baby has a developmental difficulty or congenital malformation.
- If a woman is thinking of becoming pregnant, and especially if they are over 35.
- If there are abnormal findings during pregnancy that may suggest possible genetic or chromosomal disorders.
- If a patient belongs to an ethnic group with a high incidence of genetic diseases.
A genetic counsellor’s job can be broken down as follows:
- Interpreting family and medical history to assess the risk of occurrence or recurrence of a given disease.
- Educating about inheritance, testing, management, prevention, resources and research.
- Counselling (sometimes alongside a psychologist) to promote informed decisions and adaptation to the risk or condition.
Phases of genetic counselling:
- Identify risk.
- Pre-test genetic counselling.
- Informed consent.
- Performance of molecular analysis.
- Post-test genetic counselling.
- Follow up.
As we unlock the secrets of the human genome, we are learning that nearly all diseases have a genetic component. When a genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease.
Cancer is always a genetic disease, but only 10% of cases are hereditary. Cancer can develop during life, but sometimes a person can be born with a mutation that predisposes them to it. It is thus important to study that mutation via genetic counselling. The most common types of hereditary cancers are breast cancer, ovarian cancer and colon cancer.
Most rare diseases are genetic, and they are defined as any disease that affects a small percentage of the population (less than 5 per 10,000 people). However, because there are over 7,000 different rare diseases in the world, “it is not rare to have a rare disease”. In Spain, over 3 million people have a “rare” disease, and children are most vulnerable.
Other genetic diseases
There are many types of diseases with a genetic component that can be analysed as part of the genetic counselling process, such as:
- Cardiac diseases, both with a predisposition to develop acute coronary syndrome myocardial infarction, as well as valvular malformations (bicuspid atrial valve), sudden death (Brugada syndrome), etc.
- Neurodegenerative diseases: Alzheimer’s disease, Parkinson’s disease, etc.
- Neurological diseases: Huntington’s disease, muscular dystrophies, ataxias, etc.
- Cognitive developmental disorders in children: autism spectrum disorder, attention deficit syndrome, etc.
- Metabolic diseases: obesity, diabetes, gout, porphyrias, etc.
- Cystic fibrosis.
- Rare diseases: Marfan syndrome, familial Mediterranean fever, etc.