What does SWAN / being undiagnosed mean?

SWAN stands for Syndrome Without A Name.

It is a term used to describe disabled children who are thought to have a genetic syndrome or condition that doctors have so far been unable to identify.  Many of these children have had lots of tests including blood tests, microarray, lumber punctures, EEG’s, ECG’s and MRI’s but they have all come back negative.

SWAN is not a condition, it is not a diagnosis and it does not refer to one specific syndrome or condition. In fact, the reason that many children remain undiagnosed is because it is highly likely that they have a very rare syndrome or condition.

Why is getting a diagnosis important?

Without a diagnosis life can be very isolating.  Families often feel like they don’t ‘fit in’ and without a diagnosis it can be very difficult to answer questions about their child.  They don’t know what the future holds for their child – Will they walk? Talk? What will their life expectancy be?

“Swan is the closest and only term to describe my child without reeling off a list of symptoms (or saying undiagnosed, which is meaningless.” (SWAN UK Member)

Without a diagnosis to explain why their child is disabled it can sometimes be difficult for families to have their child’s needs taken seriously.  A diagnosis, even a very rare one, means you have an answer when someone asks ‘what’s wrong’ or you have something to  write on forms.

Many families worry about having more children. Without a diagnosis it is very difficult to test or predict the liklihood of the same thing happening again and so they don’t know if future children or grandchildren might have the same difficulties.

“I say Swan because it makes me feel like we belong.” (SWAN UK member)

Many families of children with undiagnosed genetic syndromes or conditions choose to refer to their children as ‘Swans’ or ‘Swan children.’  This is because it gives them a sense of belonging to a community.

How common is not to have a diagnosis?

Even though most people do not realise it, having an undiagnosed genetic condition is actually quite common.  It is thought that about half (50%) of children with learning disabilites[1] and in approximately 60% of children with multiple congenital problems[2] do not have a definitive diagnosis to explain the cause of their difficulties. As many as 50% of children who are in contact with NHS Regional Genetics Services may not get a diagnosis.[3]

Why are some children undiagnosed?

It’s worth thinking for a moment about what we mean by a diagnosis.  For example, many children who we refer to as undiagnosed may also be described as having difficulties such as ‘global development delay’ or ‘learning disabilities.’  Or they might have medical problems such as epilepsy or hypermobility.  These labels are what we would describe as a ‘clinical diagnosis’.  They describe the difficulties a child has but unlike a genetic diagnosis, they don’t explain why the child has the difficulties they do.  The clinical diagnoses, such as learning disabilities, is one symptom of an underlying problem, not the explanation for it.  If we take a more well known genetic condition like Down syndrome we know that a child’s learning disabilities are because they have Down syndrome due to trisomy 21 (an extra chromosome 21).  If however doctors cannot pinpoint the change in a child’s chromosomes that have caused their difficulties then they are considered to be undiagnosed.

When we refer to children being ‘undiagnosed’ we are therefore usually referring to children who because of the difficulties they have (symptoms), are suspected of having an underlying genetic condition (also known referred to as a syndrome).  Children are usually suspected to have a genetic condition because of the different symptoms they have. These vary but often includes problems with their hearing or vision, epilepsy, feeding problems, unusual features, problems with their brain development, problems with their growth and joints.  In some cases these symptoms will allow a specialist to make a diagnosis quite quickly. For other children however, who may have a very rare condition it is not always so easy.  Families can go through years of testing with all the results coming back negative.

Some children may have a change in their genes that has never been seen before and so it is not part of the usual diagnostic screening process. Sometimes genetic testing may show up changes in in a child’s genes that are not thought to be responsible for their problems or there may be so many changes that doctors still can’t pinpoint which one is causing the problems.

In other instances the reason a child remains undiagnosed is because the clues gathered during the clinic appointment (the child’s development, physical examination and the family history) suggest a specific genetic syndrome which is then tested for.  If this test comes back negative it means the genetic clues have lead the geneticists to look at the wrong gene.


[1] (Hodgson, 1998; Daily et al., 2000)

[2] (Cohen, 1997)

[3] (McLaughin etc al, 2011)