After doing our general training and rotating round different specialties, dietitians will often specialise in a specific area of dietetics. Some dietitians prefer the buzz of intensive care or acute wards and others prefer to do clinics or home visits out in the community. The specialism of Inherited Metabolic Disorders (lets call it IMD for ease!) is all encompassing! Mainly out patient clinics within hospital, but the chance to also leave the hospital for home visits or meetings and then off to visit the wards or intensive care if patients are admitted. Inherited metabolic disorders are genetic inherited conditions so people are born with them and they are treated for life rather than cured. This means they will have regular visits to clinic for treatment and review so we get to know our patients well. Working with adults with IMDs means we are at the forefront of their treatment. It is a young patient population as 20-30 years ago some of these people were not surviving infancy. Now medicine and understanding is improving they are living to adulthood and leading the normal lives of adults; school, college, work, meeting people and starting families. But with this it brings new challenges – leaving home, starting work, pregnancy – lots of things to think about when following dietary restrictions and having to look after yourselves when unwell.
The majority of these disorders are due to a mutation in a single gene that affects the production or the degradation of protein, carbohydrate or fat. In most of the disorders, problems arise due to accumulation of substances which are toxic or interfere with normal function, or a reduced ability to synthesize essential compounds. Our biggest cohort of patients we look after are people with Phenylketonuria (PKU). In this disorder the enzyme that converts the amino acid phenylalanine into tyrosine is not working properly. This can lead to a build up of phenylalanine in the blood and brain which if not treated in infancy and childhood can lead to brain damage.
In adults there is a growing body of evidence that high phenylalnine concentrations in the blood and brain can cause problems with executive functioning, anxiety, low mood and reduced quality of life. A low phenylalanine diet is the main treatment for lowering phenylalanine blood and brain concentrations in PKU, so as dietitians we are an important part of their care. Other IMD disorders include disorders of fatty acid oxidation, protein disorders; urea cycle disorders and organic acidaemias and carbohydrate disorders; galactosaemia and glycogen storage disorders, which all require special diets as part of their treatment.
The thought of being an IMD dietitian can be quite daunting as we look after a number of different disorders requiring different dietary treatment, but the variety is interesting and it keeps you on your toes. Help is always at hand as we work closely with our team doctors, nurses, pharmacist, psychologist, physio and biochemists.
Our display for patients at our PKU clinic
No two days are the same. We could be in clinics seeing patients, reviewing them on the telephone or visiting them in their own homes or care homes. We receive phenylalanine results from the lab everyday and report them back to our PKU patients on the same day giving advice if need be. Our pregnant ladies with PKU need to send in blood tests twice a week, so we speak to them often and get to know them well!
We provide specialist modular feeding regimens for patients that require tube feeding and educated patients and their carers on how to look after themselves if they are unwell. We are contacted by patients if they are unwell and give nutritional advice to try and keep them out of hospital. If they do unfortunately have to come into hospital for treatment then we would see them in hospital or call our dietetic colleagues in the local hospital to give advice. Sometimes we organise events for our patients which could include an afternoon learning about pregnancy and their disorder or a meal out together so they can meet other people with the same rare disorder.
There is plenty of opportunity for research and audit and we often go to conferences (home and abroad) to present posters, give presentations or learn lots. We need to spend time reading up on the latest papers and findings for different disorders.
Poster presentation at European conference in Rome.
I hope I have given you a taste of what an inherited metabolic disorders dietitian who works with adults gets up to. More IMD dietitians will be needed in the future as patients continue to transition up from paediatric to adult services. It is such an interesting and exciting area of dietetics, interpreting the biochemical pathways and following it right through to the treatment with diet – educating, meal planning, illness management and motivating patients. Don’t be put off if you don’t have any experience in IMD as training is often provided on the job. Look out for training courses, module 4 of the BDA paediatric course is an excellent course for paediatric IMD and we are planning to put on an introduction to adult IMD course in May and don’t forget to read more about IMD’s in Adults in our new section the Manual of Dietetic Practice!