Finding common solutions for a rare disease: To mark Rare Disease Day 2021 we had a chat with Dr Katherine Howell, a paediatric neurologist who specialises in rare epilepsy, to find out more about common and rare epilepsies and how genetics holds the key for future treatments.
Tell me a bit about the work you do …
I’m a paediatric neurologist and epileptologist. These days, my work is almost solely in epilepsy. I see children with all different types of epilepsy, but my area of expertise is severe early-life epilepsies. These are conditions with frequent seizures, which are often treatment-resistant, and associated with high rates of developmental impairments. There are many different causes, most of which are genetic.
How did you get into this field?
I started neurology training and initially I said I’d do anything but epilepsy! Over time I found I was gravitating towards it, so I did an Epilepsy Fellowship at the Royal Children’s Hospital. I found the conditions fascinating, and had fantastic teachers. The combination of those two things cemented my interest and I did a full 180 from what I originally thought.
As I did more clinical training, I found myself frustrated that we were often not able to diagnose the cause of severe early-life epilepsies, and the treatments we have are often inadequate. I want to help change this, so I then got into research and have done a PhD in this area. These days, I do a mix of clinical and research work.
What does a typical day look like for you?
A typical clinical day consists of seeing patients and reporting EEG studies. I see children in two types of clinics. One is a general epilepsy clinic with children with all types of epilepsy – I see these children to diagnose their epilepsy, institute treatment and follow them up longer-term as required. The second is an epilepsy genetics clinic. Here, children with genetic or presumed genetic epilepsies are referred to me, mainly by other neurologists, for an opinion about the cause of their epilepsy or, if the cause is known, how we might best treat it.
What is the difference between common forms of epilepsy and rare forms of epilepsy?
Epilepsy is an umbrella term – there are many different types of epilepsies of varying severity, and beginning at different ages. Some of the more common childhood epilepsies are comparatively mild, occur mainly in typically-developing children, and often have a good prognosis for seizure remission.
Many (but not all) of the rare types of epilepsy are more severe, in that seizures can be very frequent or resistant to treatment, or there might be other features of the condition such as problems with development and learning, movement, behaviour and sleep.
A lot of the rare epilepsies have a genetic basis. There are a few hundred genes known to cause epilepsy. A lot of these genetic conditions have only recently been discovered in the last five–10 years, so there’s still a lot that we don’t know about each one.
What is the treatment for rare epilepsies?
For a lot of the rare epilepsies, we don’t have adequate treatment.
Predominantly, the management is to treat the seizures with anti-seizure medicines. Unfortunately, many of these don’t completely stop the seizures. Finding the genetic diagnosis is really important, as it may guide our choice of which seizure medicines to use or avoid. Sometimes this really does make a difference, markedly reducing seizures and their consequences such as repeated hospital admissions. However, even when medications do stop the seizures, they typically don’t improve other aspects of these conditions like developmental impairments, which has major consequences for the child and the family.
For the rare genetic epilepsies, what we need are treatments that address the underlying genetic problem, rather than just targeting the symptoms. Such treatments don’t currently exist for almost all of the genetic epilepsies. However, there is a lot of research happening in this area, and there are some genetic therapies in development for which there will be clinical trials in the next few years, so the prospects for us to be able to treat the underlying cause are getting better.
What is the importance of raising awareness of these sorts of conditions that are in the rare category?
Although individually rare, collectively rare diseases affect a reasonable proportion of the population, and most of them we don’t have adequate treatments for.
We need to be able to do better for children with rare epilepsies, chiefly for the devastating impacts they have on their and their family’s lives, but also because these conditions place important financial and resource burdens on health systems and society.
What are some facts about rare epilepsy that people wouldn’t know?
- Rare epilepsies collectively affect more than one in 2,000 people.
- Rare epilepsies are often very severe, particularly when they begin in infancy. The severe infant-onset epilepsies often have features other than just epilepsy and about 90 per cent of infants have problems with their development.
- Rare epilepsies often have a genetic basis. We need to develop treatments directed at the underlying cause, as our current treatments are often inadequate.
What’s the most rewarding part of your job?
There are a couple of factors:
- Seeing the progress we have made over the last few years. Although we have a long way to go, we now have fairly good access to genetic testing, which means we can diagnose the cause in many with these conditions. This is hugely important, as it means we can provide an answer for families, it helps guide prognosis, sometimes guides choice of seizure medications, and allows us to provide accurate reproductive counselling to parents wanting more children. While we’re not able to offer a cure, these things often do improve quality of life, which is rewarding.
- Seeing the amazing strength of children with rare epilepsies and their families. This provides a lot of inspiration for us to keep working hard to improve the prognosis of these conditions.