history of genetic testing?How are genetic diseases detected?

Contributed by: Anjali Dharra

What is the family history/pedigree analysis?

Family history, or pedigree analysis, is an important record of the health conditions/inherited diseases of a person and his/her close relatives. The complete record of a family’s history incorporates health information from three generations of relatives. These three generations include:

• Children
• Brothers and sisters
• Parents
• Grandparents 
• Aunts and uncles
• Nieces and nephews
• Cousins

Families tend to have a similar genetic background and most often have the same environmental and lifestyle behaviours. These factors together give clues to health conditions that may run in families. Genetic testing provides complete information about a family’s history and the causes of ongoing health conditions and the risks of acquiring new ones. 

By identifying the patterns or health disorders among relatives, expert healthcare professionals can easily determine whether this health condition persists in generations or not, just by looking at the genetic testing report in which multiple genes have been detected and identified to find out the genetic predisposition for health abnormalities and diseases. 

Family history can identify people with a higher than usual risk of many common lifestyle illnesses or disorders, such as high blood pressure, heart disease, stroke, type 2 diabetes, and certain cancers, to name a few. These disorders can be easily influenced by a combination of genetic factors, lifestyle changes, and environmental behaviours. 

In addition to this, family history can also tell about the rare health conditions that are most often triggered by a mutation in genes, namely cystic fibrosis and sickle cell anaemia.

Questions asked by the doctor while studying a family’s history:

Here is a list of questions that are frequently asked by healthcare professionals before recommending genetic testing or prediction of health conditions. These include:

1. How old you are?
2. Do you or any of your family members/relatives have/had any long-term mild or chronic health disorders?
3. How old are they, when they were diagnosed?
4. Are/were their illnesses under control?
5. How are/were they treated?
6. Where do/did they come from/belong to?
7. Did your late relatives have health problems and what were those problems?
8. How old were they when they died?
9. What were the reasons for their deaths?

Answers to all these questions aid healthcare professionals to:

• Assess the health risks based on your family history and other environmental factors.
• Recommend healthy diets and lifestyle changes to prevent or treat the diseases.
• Suggest health screening tests to diagnose the disease at the earliest.

What if you do not uncover your family’s history?

Being aware of the family health history is an important aspect that plays a vital role in adapting a lifelong wellness plan. It might be a possibility that no one in your family or relatives has any past health history or genetic disorders, but you still may have at risk of developing a health disease. This is because of the following reasons:

• Diet and nutrition
• Lifestyle behaviours
• Personal medical history
• Other environmental factors
• Being unaware of any family member’s health history
• Might have family members who died young before developing a health condition into chronic or severe stages such as cardiac diseases, diabetes, cancer, and stroke, to name a few.