Know your IMD: CSID

Know your IMD: CSID

What is it?

Congenital sucrase-isomaltase deficiency (CSID) is a genetic condition that affects a person's ability to digest certain sugars. People with this condition cannot break down the sugars sucrose and maltose.

Symptoms

After ingestion of sucrose or maltose, an affected person will typically experience watery diarrhoea, bloating, excess gas production, abdominal pain, and malabsorption of other nutrients. Other symptoms may include nausea, vomiting, or reflux-like symptoms.

In some children, these digestive problems can lead to failure to gain weight and grow at the expected rate (failure to thrive) and malnutrition. Most affected children are better able to tolerate sucrose and maltose as they get older.

Symptoms can vary for a variety of reasons including the timing of introduction of sucrose into a person ’ s diet, and the amount of sugar and starch consumed. Infants who are breast-fed or fed lactose-containing formula will often not have symptoms of CSID until they ingest juices, solid foods, or medications that are sweetened by sucrose.

Diagnosis

Endoscopic biopsy and laboratory analysis Breath test for sucrose e.g. sucrose breath hydrogen test, carbon-13 breath test Genetic testing

How is CSID treated?

In a person with CSID, dietary restrictions may require life-long adherence to a strict sucrose-free diet. This can vary depending on symptoms, but foods high in sucrose should be avoided.

In the USA an enzyme replacement therapy called sacrosidase (Sucraid) is available, however this is not licensed in the UK. Some patients in the UK may be given a similar version of this which is called Invertase.

How we support the CSID community

Metabolic Support UK have joined a community of people living with CSID, aiming to provide care for people affected by the condition whilst keeping them informed about new developments.

We have an ambassador that helps us bridge the gap between patient organisation and the community and we couldn 't be more thankful.

Moving forward as we understand more about the lived experience of CSID we 'll be able to provide more tailored support whilst empowering the community to act as advocates for their condition at the highest levels.