Session I: clinical context of genetics in primary care

1. Introduction to Genetics

Bernadette Modell

Emeritus Professor of Community Genetics, University College London

Professor Modell eloquently summarised the challenges that genetics presents to primary care, and the knowledge, skills, attitudes and tools required to provide optimum patient care in light of these challenges.

Prevention (not, for example, gene therapy) is the key goal of incorporating genetics into primary care. In order to improve prevention, practitioners need to adjust their focus from individuals to whole families. They will have to cope with the diversity of risks associated with different conditions and populations, and the diversity of families and kinship patterns they may encounter. The major issues for primary care to address are the personal risk for a patient, their reproductive risk, and the risk to other family members.

Data were presented to illustrate the extent to which practitioners’ local populations are affected by genetic conditions. For example, the UK average for just six screenable disorders per 10,000 residents is more than 0.7 conceptions annually. In parts of London this rises to almost 1.2 conceptions annually per 10,000 residents. The number of people who need to know their carrier status varies across the country from just under 500 to almost 800 people per 10,000 residents.

Critical to managing genetics in primary care are:

Knowledge – basic genetics

Skills – family history taking

Attitudes – non-directive counselling

Tools – genetic information resources

Knowledge : A summary of basic genetic information was given including the difference between mutations giving rise to single gene disorders and those that contribute to multifactorial disorders or that alter the response to, for example, specific drugs. In addition, inheritance patterns were explained and forms of genetic diagnoses discussed.

Skills : The key skill is family history taking, enabling a GP to identify relatives of their patient who may have disorders relevant to their patient’s health, and to that of other family members. Disorders “discovered” this way may not otherwise have been considered as important to these patients. The prevalence of first cousin parents (nearly 7% in parts of the UK) means careful family history taking is essential to understanding inheritance and risk within a family. However, there is a need for cost- and time-efficient methods to elicit, record and present the genetic element in the primary care family history.

Attitudes and Tools : Following risk identification, the key follow-up intervention by practitioners is giving information (about risk to the individual, their children and to other relatives) and advice (lifestyle etc.) to help patients reach informed decisions. Interventions such as seeking expert advice or referring to a specialist are less commonly required, but it is important to know where to go to for this help (see the summary of Dr Fred Kavalier’s presentation).