Spinal Muscular Atrophy with Respiratory Distress (SMARD)

This information sheet provides an introduction to the cause, effects and management of Spinal Muscular Atrophy with Respiratory Distress. It is for families of children diagnosed with SMARD and may also be useful for healthcare and other professionals.

Further information on SMARD, daily living and sources of support is available from SMA Support UK’s online route map for SMARD.

SMARD is a complex condition; there is a lot of information to take in and every child with SMARD is different. You can always ask your child's medical team to go over any of this information with you. 

What is SMARD?

SMARD stands for Spinal Muscular Atrophy with Respiratory Distress. It is sometimes also called SMARD1, Distal Spinal Muscular Atrophy 1 (DSMA1) or distal Hereditary Motor Neuropathy Type VI (dHMN6 or HMN6). There are also later onset forms of SMARD such as DSMA2, DSMA3, DSMA4 and DSMA5. 

SMARD is a severe, inherited neuromuscular condition that specifically affects nerve cells in the spinal cord called lower motor neurons. Usually, signals from the brain are sent via the spinal cord along the nerve cells and through to muscles. This makes it possible to consciously contract the muscles and to make them move. In SMARD, the lower motor neurons degenerate, impairing the link between the brain, the spinal cord and muscles. These muscles can no longer be stimulated, which causes them to waste (atrophy). 

The first and most noticeable symptom of SMARD is usually breathing difficulties (respiratory distress). This is caused by paralysis of the diaphragm, the large, thin sheet of muscle separating our chest from our stomach that is essential for normal breathing. In SMARD1 this usually occurs in an infant’s first year of life. Along with this, and usually progressing rapidly after the onset of breathing difficulties, there are signs of weakness in the muscles which enable walking, crawling, arm and hand movement, head and neck movement and swallowing. 

Other early symptoms of SMARD can include foot deformities and a weak cry. Some children have fatty finger pads. Other signs may also be present before birth, for example during pregnancy some babies do not put on weight at the expected rate and some mothers may notice a reduction in their baby’s movements towards the end of the pregnancy.

Nerves for sensation and controlling bodily functions (the autonomic nervous system) may also be affected by SMARD. This can lead to symptoms such as excessive sweating, an irregular rate or rhythm of the heart (cardiac arrhythmia), constipation, bladder incontinence and a reduced response to pain. 

SMARD is an extremely rare disease and the number of children affected is very small. Currently, it is not possible to collect accurate numbers of those affected but this may change as knowledge of the condition increases.

What causes SMARD?

Spinal Muscular Atrophy refers to a group of inherited conditions affecting muscles and nerves that occur due to changes in an individual’s genetic material. The variety of genetic causes and use of different names can be very confusing but the diagnosis Spinal Muscular Atrophy with Respiratory Distress (SMARD) usually refers to a rare form of SMA called SMARD1 which is caused by a mutation (permanent change in the DNA of a gene) in the IGHMBP2 gene (immunoglobulin mu-binding protein 2) on chromosome 11q13.3. 

More than 60 different mutations in the IGHMBP2 gene have been found to cause SMARD1. Most of these mutations affect the amount of, or the functionality of, IGHMBP2 protein produced by the IGHMBP2 gene. Although the exact mechanism is unknown, if the IGHMBP2 protein is not working properly or there is not enough of it this leads to the degeneration of the lower motor neurons.  

It is thought that the amount of functional protein the mutated IGHMBP2 gene produces may be linked to the severity of SMARD1 an individual has. The less functional IGHMBP2 protein a person has, the earlier they are likely to develop symptoms. However, considerable variability has been described even between individuals who have identical changes in the IGHMBP2 gene, suggesting that other factors may also have an effect. 

SMARD1 is an autosomal recessive genetic disorder. For further information about the genetics of the condition and how it is inherited, please see our information sheet: The Genetics of some rarer forms of SMA

Later onset forms of SMARD, such as DSMA2, DSMA3, DSMA4 and DSMA5, are caused by mutations on different genes and chromosomes. As research continues, more information about the genetic variants may become available.

If you have a child with SMARD, you should be offered a referral to a clinical genetics servcie for genetic counselling. You can also request a referral from your General Practitioner (G.P.)

Genetic counselling is with a healthcare professional who has expert training in genetics. They will answer any questions you have about your genetic circumstances, arrange any further genetic testing that may be necessary and will provide you with advice and information.

How is SMARD diagnosed?

As SMARD is a very rare condition, it may sometimes go unrecognised. Obtaining a diagnosis can be a lengthy process taking several months and in some cases it may not always be possible to confirm the diagnosis.

If SMARD is suspected, a blood sample will be taken from your child for genetic testing to help confirm the diagnosis. Further tests, such as an electromyogram (EMG) or muscle biopsy, may be considered if there is uncertainty. 

SMARD is usually diagnosed following severe breathing difficulties (respiratory distress). Some children are very weak and show symptoms within the first 3 months of life. Other children are relatively strong and are usually diagnosed later on in their first year of life.

How does SMARD progress?

There is a wide range of severity in SMARD and how it progresses varies widely between individual children.

Once a child with SMARD starts to show symptoms of respiratory failure they will require mechanical ventilation to survive. For example, a tracheostomy (surgery to create an opening in the windpipe to allow breathing through a tube rather than the mouth). This is a significant intervention and any family facing this option will have the opportunity to have a full and careful discussion with their medical team as to whether this step is the most appropriate for their child. 

It is difficult to predict life expectancy because the progression of SMARD varies between individual children, as does the use of appropriate medical interventions to support breathing. Typically, the health of a child with SMARD will deteriorate rapidly within the first two years of life. This may be followed by a period when their health remains stable (this may be described as a disease plateau). Some children may even show some improvement after the age of two years. Sadly, in common with other conditions which result in severe muscle weakness, life expectancy for children who have SMARD is reduced. 

Is there a treatment or cure for SMARD?

There is currently no treatment or cure for SMARD. Once your child has been diagnosed, you and your child’s medical team will need to discuss which possible medical interventions are in the best interests of your child.

Discussions will assist in developing a plan for your child’s care, including their care in a medical crisis. Broadly speaking this may focus on palliative care services - providing quality of life care and symptom control; or, as mentioned above, more invasive medical management involving a tracheostomy.

These are all very difficult discussions and you should have time and support to consider the options thoroughly with your child’s medical team. 


To find out more about the latest published SMA research and clinical trials please go to the SMA Support UK research pages. 

For information specifically on SMARD related research please click here.

As new treatments for SMA are being developed, they need to be tested in clinical trials. The UK SMA Patient Registry is a database of genetic and clinical information about people affected by SMA. The Registry also helps specialists gain more knowledge about the condition and the number of people affected by SMA. This information helps to develop and improve worldwide standards of care for people with SMA. Currently in the UK there is not a registry specifically for SMARD. The UK SMA Patient Registry is mainly for people affected by SMA due to mutation in the SMN1 gene, however the registry does accept registrations from people affected by Spinal Muscular Atrophy with Respiratory Distress (SMARD) with mutation in the IGHMBP2 gene. More information is available on the UK SMA Patient Registry website. You can also contact the Registry Curator by e-mail: registry@treat-nmd.org.uk or phone: 0191 241 8605.

What healthcare and support is there?

- Referrals

Once your child’s diagnosis has been confirmed, a referral should be made to a consultant neurologist or paediatrician with expertise in neuromuscular conditions so that you can discuss the diagnosis, learn more about care options and develop a care plan for your child. 

Children with SMARD will also be referred to healthcare professionals in a number of specialties. These may include community nursing, genetics, palliative care, respiratory medicine, physiotherapy, orthopaedics, occupational therapy, speech and language therapy, and dietetics. All of these professionals together are sometimes called a multidisciplinary team. One of the team should act as your keyworker; their role is to help co-ordinate services for your family. You can find out more about how these people can help in SMA Support UK’s leaflet ‘Who’s Who of Professionals’. 

Although families are often willing to travel significant distances in order to see specialists, babies with SMARD may not tolerate long journeys well so, where possible, lengthy journeys should be avoided. To help with this the consultant may arrange for your child’s ongoing care and support to be shared with local health services. 

-    Genetic counselling 

Following your child’s diagnosis you should be offered genetic counselling. A referral to genetic services is usually made through your General Practitioner (GP), paediatrician or neurologist.  

A genetic counsellor is a healthcare professional who has expert training in genetics. They will explain how SMARD is inherited and what the chances are of other family members also being affected. Genetic counselling also provides the opportunity to discuss options and choices for any future pregnancies. Genetic counsellors can also be contacted at a later date to discuss any further questions you may have. 

Further information on the genetics of SMARD and future pregnancy options can be found in the SMA Support UK SMARD route map. 

- Advance care plan

Ideally the goal of care is to enable a child with SMARD to enjoy a good quality of life at home with their family with a minimum of hospital admissions. It is important that you have the opportunity to discuss in-depth with your medical team the range of care options that may be available. These discussions are important for developing an advance care plan to record the treatment you wish, or do not wish, your child to receive if his/her health deteriorates or in an emergency situation. This plan can be reviewed and you can change your mind at any time. With your permission, this advance care plan can be shared with professionals supporting your child, including ambulance services, to ensure that everyone is aware of your wishes. 

Open access to your local children’s ward can be arranged with your medical team so that, whenever needed, you can take your child straight to hospital. 

- Palliative care

Palliative care is an active approach to care, aiming to support the physical, emotional and practical needs of your child and family from the point of diagnosis onwards, and also takes into account any cultural and spiritual needs you may have. Palliative care includes the management of symptoms, information and practical support, and the provision of short breaks for parents / carers. The overall aim is to achieve the best quality of life for your child, whichever medical options you may choose.

Palliative care services vary across the UK and may be provided by a number of different healthcare professionals in a variety of settings including hospitals, children's hospices and at home. Your child’s consultant, care advisor or specialist nurse can advise you on services available in your area. 

- Children’s hospices

Children’s hospices offer a wide range of services and support to children with life-limiting conditions and their families throughout the UK. Staff at children’s hospices support families, both practically and emotionally. Support and respite is available to families at any stage of their child’s life. Many families find hospices to be happy and positive environments where they can spend time together taking part in activities as a family, including any siblings. 

Care and support is provided by specialist staff and, as well as offering nursing care, they provide a range of services that may include physiotherapy, complementary therapies and play and music therapy. 

The hospice can support you to make decisions about your child’s ongoing care and wishes for their future care should they become unwell. 

Children's hospices can also offer invaluable support and specialist care at end of life both within the hospice and sometimes in your own home, and they will also provide practical and emotional support if a child dies.

- Planning for going home

If it is possible for you to take your child home then communication with your community team will start so that support is available for you when you get home. You will need a great deal of practical support and a detailed care package will be set up before your child is discharged from hospital. This often takes a long time to organise. You should also receive information and advice on financial, practical and emotional support available in your local area to supplement the care package.

The care package will most likely cover the following topics:

•    Housing
•    Equipment and supplies
•    Day and night time carers / who will provide this service / hours and rotas
•    Respite care
•    Procedures to cover emergencies
•    Getting out and about - including play, leisure and education
•    Sources of financial help
•    Sources of support - including those in your local area

Further information on these topics is available in the SMA Support UK SMARD route map. 

-    Looking after yourself

The impact of a diagnosis of SMARD on families is enormous. It often comes as a shock and you may experience feelings such as disbelief, confusion, anger and sadness. You may find it difficult to take everything or anything in. The 24 hour-a-day responsibility of caring for a child with complex medical needs that follows can be physically, emotionally and psychologically exhausting. 

Everyone is different, but it is important for you and your family to have access to emotional support and to have plenty of time to talk and ask questions. This can be with members of your child’s medical team, your local GP, health visitor, social worker, psychologist or a counsellor, family and friends, a spiritual leader, support groups, or online communities. (More information on this is available in the ‘Emotional and Social Support’ section of the SMARD route map.) 

Even though you will be focused on your child it’s important to try and look after yourself. Remember to make sure your vaccinations are up-to-date and that you get the influenza vaccine (flu jab). Perhaps ask friends and family to help out with practical things such as shopping and cleaning to help save you time and energy. 

You may also benefit from accessing local short break services. These may be available in the home or a children's hospice. Some local authorities also have residential short breaks provision for children with disabilities. You can ask your GP, community nurse, health visitor or social worker for more information.  

-    Financial support

You may be eligible for a number of financial benefits to help towards the cost of providing the extra care your child needs. This does depend on your individual circumstances. For further information visit the website: https://www.gov.uk/

Your health visitor, community nurse, neuromuscular care advisor, family support worker, social worker or outreach worker may be able to help with applications for financial benefits.

There are also a number of charities that can assist with the cost of general household goods, specialist equipment and holidays / days out. Please contact SMA Support UK for more information or see the SMARD route map.

What other help is available?

Spinal Muscular Atrophy Support UK provides free information and support to individuals and families in the UK affected by SMA. Leaflets including ‘Who’s Who of Professionals’ and ‘Toys and Play’ can be found on our website. Our outreach workers are able to visit you at home and / or be in touch by phone or email. They offer personalised support and information and are available to talk things through and to answer questions. They can discuss the support available to families. Please note, we do not give medical advice. Multisensory toy packs are also available free of charge for babies in the UK diagnosed with SMARD. 

Muscular Dystrophy UK provides information, support, advocacy services and grants towards specialist equipment for people affected by a range of neuromuscular conditions. 

Regional care advisors and sometimes neuromuscular nurse specialists, are attached to NHS neuromuscular clinics in various regions of the UK. They provide support and information to children and adults with muscle diseases and their families. They link up with other professionals and services so that people receive the local health and social support they need.

Useful contacts

SMA Support UK
Phone: 01789 267 520
Email: supportservices@smasupportuk.org.uk
Website: http://www.smasupportuk.org.uk/
For more detailed support and information about SMARD please go to the SMARD route map

For more information about the genetics of SMARD and how it is inherited, please see The Genetics of some rarer forms of SMA.

Muscular Dystrophy UK
Phone: 0800 652 6352
Website: http://www.musculardystrophyuk.org/ 
Regional Care Advisors
Contact details are available through Muscular Dystrophy UK’s website: http://www.musculardystrophyuk.org/get-the-right-care-and-support/people-and-places-to-help-you/care-advisors/

Together for Short Lives
Provide information and support to families who have a child with a life-limiting condition.
Phone: 0808 8088 100
Website: http://www.togetherforshortlives.org.uk/

Contact a Family
Provide information and support to families who have a child with a disability.
Phone: 0808 808 3555
Website: https://www.cafamily.org.uk/

UK's largest charity funder of children's specialist disability equipment.
Phone: 0800 902 0095
Website: http://newlifecharity.co.uk/

Turn2us helps people in financial hardship gain access to welfare benefits and charitable grants.
Website: https://www.turn2us.org.uk/

If you have any feedback about this information, please do let us know

Author: SMA Support UK Information Production Team
Version: 4.1
First published: March 2015
Last reviewed: May 2017

Updated February 2018
                                               Next full review due: May 2020 


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