Genomics in general practice


Family history
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Practice point


Ideally, a three-generation family history should be collected on all patients where possible, including first-degree relatives (ie children, siblings, parents) and second-degree relatives (ie aunts, uncles, grandparents).1

The use of a family history screening questionnaire1  can help identify individuals who may require a more detailed assessment of their family history of cancer, heart disease or diabetes


What do I need to know?


Family history is particularly useful for assessing the risk of autosomal dominant inheritance and multifactorial inheritance. Conditions with an autosomal dominant inheritance or X-linked recessive inheritance pattern will often occur in the absence of family history (eg cystic fibrosis [CF]).
General information to collect in a family history include:4

  • age of patient
  • age at diagnosis of conditions in the family
  • ancestry and cultural background
  • step-relationships and adoption
  • children born to parents who are blood-related (consanguinity)
  • known genetic conditions.4

Update the patient’s family history, including births, deaths and new diagnoses opportunistically. Markers of possible genetically determined conditions in a family history include:1,3,4

  • birth defects, multiple stillbirths and multiple miscarriages – consider referral to genetics services
  • developmental delay (DD) – consider referral and ordering a chromosome microarray (CMA) and Fragile X syndrome (FXS) testing (DD and intellectual disability [ID], FXS, autism spectrum disorder [ASD])
  • neurodegenerative conditions, premature ischaemic heart disease, sudden death – consider referral to genetics services
  • early onset of common cancers and/or unusual combinations of rare cancers – refer to eviQ online2 for further information about familial cancer syndromes.

 
 

Pedigree


Drawing a pedigree can be helpful in identifying patterns of inheritance (Table 1).

Table 1. Common pedigree symbols

Record the date on which the pedigree is drawn and update it as new information becomes available. At each step, ask about the health of the family member being discussed. It may not always be possible to complete the pedigree because of complexities such as adoption, a lack of reliable information or family disruption. It is important to consider such issues in each family. Step-by-step instructions for drawing a pedigree is shown in Table 2.

Table 2. Step-by-step instructions for drawing a pedigree

Resources for general practitioners


National Genetics and Genomics Education Centre (UK), Taking and recording a family history
The Royal Australian College of General Practitioners


Genomics in general practice




 

 

  1. The Royal Australian College of General Practitioners. Guidelines for preventive activities in general practice. 9th edn. Melbourne: RACGP, 2016.  [Accessed 22 December 2017].
  2. Cancer Institute NSW. eviQ. Sydney: Cancer Institute NSW, 2017 [Accessed 22 December 2017].
  3. Bennett RL, French KS, Resta RG, Doyle DL. Standardized human pedigree nomenclature: Update and assessment of the recommendations of the National Society of Genetic Counselors. J Genet Couns 2008;17(5):424–33.
  4. Bennett RL. The family medical history as a tool in preconception consultation. J Community Genet 2012;3(3):175–83.

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