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About the study

Newborn Screening for SMA - Introduction

1 in every 10,000

In the UK, parents can have their baby screened for 9 health conditions when they are 5 days old. This involves taking a small amount of blood from the baby’s heel (blood-spot or heel-prick test). Most parents choose to have their baby screened.

If the baby has one of these conditions they will be referred for treatment straight away - sometimes this is before they have symptoms.

It is possible to use the same blood sample to screen for more conditions and this survey is about whether a condition called Spinal Muscular Atrophy (SMA) should be added to the blood-spot test.

SMA is a genetic condition that affects how the nerves and muscles function together.

Around1 in every 10,000 babies born in the world has SMA, which means about70 babies in the UK are born with it each year.

Roughly 1 in 40 people are ‘carriers’ of SMA, which means that they have a change in one of their genes. Carriers don't have SMA because they have one working copy of the same gene, but if two carriers have a baby together their baby can have SMA.

Usually, people will not know that they are carriers until they have a child diagnosed with SMA.

inheritance SMA

Each year in the UK, around 40 babies will be born with the most severe type. They will have problems with breathing, swallowing and movement and without treatment, are unlikely to live past two years of age.

Around 30 babies each year are born with a type of SMA that causes significant disability. They don't develop the ability to stand and walk, or they lose these abilities, and will need to use a wheelchair. They may need help with eating, breathing and daily activities.

Up to 3 or 4 babies will be born with 'later-onset' types of SMA, which cause progressive muscle weakness that can, over time, affect daily living (e.g. walking, dressing). A small number will develop symptoms as teenagers, but for most, symptoms won't be noticeable until their 20s or 30s - this is called adult-onset SMA.

Drug Treatments

There were no drugs to treat SMA, but 3 are now available on the NHS. They cannot repair damage already caused, but they can stop more damage from happening or slow down muscle weakness.
 
In research trials, many children given these new drugs (as babies) achieved milestones that would not otherwise have been possible. Many babies with the most severe types are surviving into childhood and many children who would have developed significant disabilities are developing in similar ways to children without SMA.

The treatments work best when given as soon as possible and preferably before symptoms start. Currently, most children are diagnosed from their symptoms and permanent damage has happened. Newborn screening could give babies with SMA the the greatest chance of benefitting from treatment.

If screening can benefit many babies born with SMA, then why do we need your views?

The UK National Screening Committee (UK NSC) advises the Government on screening and they are currently reviewing whether SMA should be added to the heel prick test. They will consider a wide range of issues because screening can have other impacts, including causing harm to some people, and opinions can differ on how important these other impacts are.

One of these issues is that the NHS will currently only offer the new treatments to babies expected to develop SMA symptoms as children

The 3 or 4 babies born each year expected to have later onset SMA, will not be eligible for treatment when diagnosed. Instead, they will be monitored.

  • Any who develop symptoms as children / teenagers will be offered treatment (they may have some irreversible damage by this point)
  • Most are likely to develop symptoms as adults and will not be offered the treatments at any point. People living with adult-onset SMA are usually offered physiotherapy and support with their living needs (such as walking aids).

Knowing that their baby is likely to develop symptoms, but not knowing when, and not being able to prevent this from happening, could cause stress and anxiety and have a long-term harmful impact on the family and the child.

Some people may prefer not to know, as it could cause years of worry over something they can’t change.

Some people may prefer to know, because;

  • they can look out for symptoms starting in childhood(which would make them eligible for treatment),
  • it gives them time to prepare,
  • it might save them from searching for a diagnosis when symptoms start.

Screening for genetic conditions can affect parents and their wider families.

Screening can make parents feel more anxious about their baby's health when they might not have been worried. Parents may find diagnosis through newborn screening particularly distressing if they weren't prepared for the possibility of a positive result, and if their baby appears well at the time.

mother holding and kissing baby
A positive result can affect whether / how parents decide to have more children as they could have another child with SMA.

Other family members may also discover that they could have a child with SMA -some may see this as useful information whereas others may prefer not to have known.

Why does your opinion matter?

We want to know your views on the potential harms and benefits and whether you would support SMA newborn screening. We will be asking members of the public, families living with SMA, healthcare professionals and parents being approached to take part in an SMA screening pilot. The results will be presented to the UK NSC to help them with their decision.

You can watch this introduction as a presentation hereLink opens in a new window (video opens in YouTube).