Genetic testing – guidelines needed suggest researchers

The 24th International Symposium on ALS/MND began in Milan today with a record number of over 950 delegates attending to hear the latest news in MND research.

Inherited MND is a rare form of MND characterised by a family history of the disease. Over recent years more and more genes have been discovered, which has lead to an increase in individuals wishing to pursue genetic testing.

Read more about inherited MND on our website

A genetic test consists of a sample, which is then sent off to a genetic laboratory. Here the blood sample is then screened for the MND-causing genes.

The gene that is faulty in inherited MND can differ between one affected family and another. Mistakes in genes called SOD1, TARD-BP, FUS and C9ORF72 between them account for about 65 – 70% of cases of inherited MND. Scientists have yet to identify the gene defects that cause the remaining 30%.

Find out more about genetic testing for inherited MND in our information sheet

However, what guidelines are currently in place for people living with MND and wishing to pursue genetic testing? The symposium began today in Milan, with Prof Orla Hardiman (Dublin, Ireland) asking ‘To test or not to test?’ in her plenary talk, and Dr Stacy Rudnicki (University of Arkansas for Medical Sciences, AR, USA) looking at the challenges facing MND clinics worldwide.

Prof Orla Hardiman – to test or not to test?

A few years ago we thought that MND was a relatively simple disease with two sub groups:

• Those with a family history (known as inherited MND)
• Those without a family history of MND

However, since the discovery of C9orf72 in 2011, researchers still cannot seem to agree on a definition for inherited MND.

When it comes to genetic testing Prof Hardiman highlighted in her presentation: “Because some of the MND-causing genes are associated with other diseases (such as frontotemporal dementia) this means that testing, and subsequently genetic counselling may become a problem.”

So, inherited MND goes from a simple disease (Gene = MND) to complicated (Gene = lots of other diseases + MND).

However, it’s not just this over lapping of diseases that becomes a problem in genetic testing. Some people living with MND develop cognitive impairment, meaning that genetic counselling could be a challenge.

Inherited or not? 

A diagnosis of inherited MND is only given if there is a clear family history of the disease. Prof Hardiman brought to our attention that in smaller families this family history may not be so apparent. Not only this, some of the MND-causing genes are relatively new (C9orf72 was only discovered in 2011).

“MND is a complex genetic disease and we still do not completely understand the genes involved, nor how likely they are to pass down the disease from one generation to the next.”

Another issue for genetic testing is that there are still approximately 30% of genes that we are yet to identify but this will inevitably change over time.

Guidance

Prof Hardiman stressed: “We really need to develop guidance in terms of genetic testing and counselling in MND. We also need a quality assessment of the genetic counselling process to ensure people living with inherited MND are receiving the best possible service.”

Stacy Rudnicki – what are MND clinics doing?

Dr  Rudnicki continued on with the theme of genetic testing in MND. But, unlike Prof Hardiman who focused mainly on what’s happening in Ireland, she presented her findings from a worldwide survey of MND clinics.

Echoing Prof Hardiman, Dr Rudnicki explained in her introduction: “20years ago we only knew that the SOD1 gene caused some cases of inherited MND. Nowadays the genetics of MND has become a lot more complicated.”

She collected results from 87 MND clinics around the world and presented her results to delegates at the symposium clinical session.

It was assuring to know that all MND clinics had a genetic counsellor/geneticist available. However, 84% of clinics said that they would test for an MND-causing gene themselves – before counselling! It was stressed that this would need to change in order for those affected by inherited MND to receive the best care.

The challenge

The main challenges identified by Dr Rudnicki’s survey were that clinics are uncertain of the meaning of a positive test result for an MND causing gene when there is no family history of MND. Another challenge identified was that some MND clinics had limited knowledge of new genes, and as Prof Hardiman highlighted, this is likely to change over time.

Dr Rudnicki agreed with Prof Hardiman about guidelines needed for genetic testing in MND. She added that there are currently Italian and European guidelines which state:

All people living with MND should discuss genetic factors with their neurologist. Those with a family history of MND or frontotemporal dementia should be offered testing’ – highlighting the need for MND specialist neurologists to be genetically literate.

What do our Care Centre Co-ordinators say?

Ruth Glew (South Wales Care Network MND Care Centre Co-ordinator) is attending this year’s symposium. Speaking ahead of the meeting in Milan she spoke to us about genetic testing in MND:

“ We are now aware of four main genes associated with inherited MND, and there is the potential of others being discovered in the future. This is an exciting time. At another level, genetic testing for people living with MND and subsequently their at risk relatives (should an MND-causing gene be found) becomes possible.

“Genetic testing is rarely straightforward. There are issues of penetrance and variability and also the physical, psychological and social ramifications for the person being tested and their family to consider. Neurology and genetic health care professionals need to work together to develop guidelines for genetic testing in MND to enable the best quality of care for those individuals and families who want to consider genetic testing.”

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