Minutes of the Exeter Sessional GPs GroupDarts Farm – 7 February 2017

The meeting was kindly sponsored by:

TevaRob

ChiesiChristina

PfizerJames

Attendance:Approx 15 members

Welcome:

Dr Tim Dyke opened the meeting and thanked the reps for sponsoring. Also when you sign in for the meeting please write your forename and surname clearly (for the benefit of the reps.).

Dr Donald McLintock circulated some lists for members to write details of useful apps used for work related purposes. He will be putting details on the web site.

Tim welcomed the speaker Dr Guy Bradley Smith – retired GP from St Thomas and currently several roles including Hon Clinical Lecturer UEMS and Standing Member for NICE QSAC2. Of relevance to his talk, he is also a co-author of the Oxford Handbook of Genetics.

Clinical meeting

Genetics in Primary Care - Dr Guy Bradley Smith

Prevalence:

Single gene or multi-factorial disorder affecting the patient and at least two family members – approx. 10% in North London – but this is likely to be higher than most of UK owing to high number of Ashkenazi Jewish people and also people of Caribbean origin.

Percentage of people age under 60 who are affected by disease at least partially determined by genetic factors is estimated to be 60%.

Some challenges:

When to ask about family history – e.g. at time of cancer diagnosis, pre-conception, at time of other diagnosis.

How to record – e.g. draw a pedigree and scan on to notes.

How to keep the family history updated.

How practical is this – not very in short consultations as it takes time.

Some examples of dilemmas:

Relative known to be terminally ill with ca breast at young age – to assess risk of other family members, a piece of tissue from the index case is needed.

Army entrance questionnaire – 17 year old says no genetic disease in family, you are asked to verify and you know there are genetic issues in parent. What to do – complex issue of preserving confidentiality – you don’t know if 17 year old has been told by parents, you don’t know if he has told parents he is applying to army, telling the truth and not leaving anything out.

The following mentioned in the lecture is very detailed (49 pages) but has some useful flowcharts in the appendices:

Consent and confidentiality in clinical genetic practice: Guidance on genetic testing and sharing genetic information

A report of the Joint Committee on Medical Genetics

Each person has 3 x 109 base pairs and we share 98% of DNA with unrelated humans.

Epigenetics – the biochemical process that turns genes on and off.

Single gene disorders. Looking at a pedigree makes it easier to spot a pattern compatible with autosomal dominant, autosomal recessive (both parents of a case are obligate carriers) and X linked recessive. However variable penetrance (genotype not showing phenotype) makes it more difficult.

Mitochondrial DNA – inherited from mother.

Chromosomal abnormalities – extra, missing or translocation (Robertsonian 14:21 is a particular example leading to inherited Down’s syndrome).

Polygenic – normal distribution. These are common, the genetics is complex. The frequency (y axis) against liability (x axis) curve is a normal distribution. If one family member is affected then the curve for that another person in the family shifts to the right.

Ante natal and new born screening – amazingly all done without expressed consent – e.g. haemoglobinopathies, Down’s, neonatal blood spot tests for sickle cell, congenital hypothyroid, cystic fibrosis and six inherited metabolic diseases.

Getting information:

  • CCG funds Peninsula Genetics to give phone advice – so take advantage of it:

01392 405726. Web site is .

  • Northern primary care genetics has useful section on cancer genetics: .
  • NICE referral guidelines for familial breast cancer: .

Amsterdam criteria 3,2,1

Developed to help decide who should be tested for hereditary nonpolyposis colorectal cancer:

  • 3 affected relatives
  • Across 2 generations
  • At least one diagnosis made under age 50.

Remember that hereditary cancer only accounts for 5% of all cancer.

Diagnosis:

  • Think of the possibility
  • Ask about family history
  • Draw the pedigree
  • Mode of inheritance? – can you see the pattern?
  • Use guidelines
  • Discuss with genetics

What we want to know:

  • Diagnostic – what?
  • Predictive – will I get it?
  • Carrier testing – am I part of the problem?

Predictive genetic testing for significant genetic disease and genetic testing of children should not be undertaken in primary care.

Contrast this position with direct to consumer testing for which there is currently no regulation! Not presented by Dr Bradley Smith but rather worryingly I discovered adverts for it on the RCGP website of all places!!!:

Personal genomics:

  • Accuracy
  • Presentation
  • Timing
  • Clinical utility
  • Cost effectiveness

Pharmacogenomics – influence of genetic variation on individual’s response to a drug.

Further learning

Genetic advances in medicine: has the promise been fulfilled in general practice?

Fiona M Walter and Jon D Emery

Br J Gen Pract 2012; 62 (596): 120-121.

Future ESGPG Meetings

7th March 2017Older People’s MedicineDr Paul Mudd RDE

Meeting time

Please note that the meetings are now scheduled to start at 7pm with the guest speaker planned to commence at 7.30pm.

Committee Contacts

Dr Ross Hemingway (chair)

Dr Anna Beazley (treasurer)

Dr Tim Dyke (education co-ordinator)

Dr Anna Griffiths (funding co-ordinator)

Dr Felicity Knott (web site co-ordinator)

Dr Kathryn Shore (minutes’ secretary)