Rare diseases in clinical practice

In November 2013 the UK government launched an initiative to raise awareness of rare diseases, publishing a strategy document.

The aim is to promote better patient management through recommending that doctors and other health professionals should:

  • know to recognise patients who may have these conditions; and
  • be aware of the availability of informed specialist advice and expertise – including specific treatments or related research opportunities – from which their patients can benefit.

NGGEC invites you to visit our new pages about rare diseases in the ‘I’m in Clinical Practice’ section of our website.

As a brief summary, there are an estimated 7,000 different ‘rare diseases’ (of which more than 2,000 are already well characterised), which together affect 1 in 17 people in the population at some time in their life. A ‘rare’ disease is defined as one which:

  1. has an incidence of less than 1 in 2000 people;
  2. is a life-threatening or chronically debilitating disease; and
  3. requires special combined efforts to enable patients to be treated effectively.

More than 80% of ‘rare diseases’ are genetic disorders, the vast majority being due to differences in DNA sequence or copy number affecting a single gene or gene pair.  Many of these disorders can now be diagnosed from specific genetic testing, although access to the testing may need to be through a recognised specialist clinician.

For many of these disorders, not only is there diagnostic expertise in the UK, albeit concentrated in one or a few centres, but also an optimal management plan or treatment for the condition, usually informed by closely linked research, and available through the expertise at the centres.

The UK Rare Diseases initiative also forms one of three arms of the UK government’s 100,000 Genomes Project, under the auspices of Genomics England. The rare diseases arm will involve 10,000 individuals with disorders that are known to be, or likely to be, due to alterations in single genes, but where those genes are not yet recognised. Whole genome sequencing will be used to find the underlying genetic alterations, ultimately for the clinical benefit to the patient and their family, and for similar families.

The genetic and clinical characterisation of new rare diseases also forms the basis of the DDD (Deciphering Developmental Disorders) project, which is using whole exome sequencing to identify causative genetic alterations in children with learning disabilities, and has a recruitment target through clinical genetic services of 12,000 individuals, together with DNA samples from both parents.

Further information about these initiatives is provided in our website’s new section on rare diseases. This includes details of the NHS list of nationally funded specialised services, and lists from the UKGTN (UK Genetic Testing Network) of the individual conditions for which genetic tests are available to the NHS, and the centres that offer specialist clinics for those conditions.

We hope you will visit the website, and we welcome your comments on our rare diseases pages, and suggestions for any additional material that may be helpful.