SMA with Lower Extremity Predominance (SMA-LED)

This information is for if your child has been recently diagnosed with SMA - LED.

What is SMA - LED?

This rarer form of SMA begins in infancy or early childhood and progresses slowly. Children have weakness in their leg muscle weakness which is most severe in their thigh muscles (quadriceps). Children and adults often have a ‘waddling’ or unsteady walk and have difficulty getting up from sitting and climbing stairs.

There’s limited information about SMA-LED because it’s so rare, but your child’s medical team will be able to discuss how it affects your child and how to manage symptoms for maximum comfort and quality of life.
 

Which gene is affected?

Some of the genes that cause rarer forms of SMA are associated with more than one condition, so please be aware that the website links suggested might provide information that is not just about SMA.

The affected gene is:

  • DYNC1H11

Further information can be found here.
 

Inheritance pattern

SMA-LED has an Autosomal Dominant inheritance pattern.

To find out more about this please see our information sheet ‘The inheritance patterns of some rarer forms of SMA’.


Support and resources

Though not a substitute for professional medical advice, the US National Library of Medicine, Genetics Home Reference provides more information which you can find here.
 

SMA UK
Phone: 01789 267520
Website: www.smauk.org.uk

Provides information and support for anyone in the UK affected by any form of SMA.
 

Contact
Phone: 0808 808 3555
Website: www.contact.org.uk           
Provides information and support for families with children with a disability

Version: 1.1
Author: SMA UK Information Production Team
Published: August 2018
Last updated: March 2019

Next full review due August 2021

References

1. Harms et al. (2012) ‘Mutations in the tail domain of DYNC1H1 cause dominant spinal muscular atrophy’, Neurology, 78, pp. 1714-1720.

 

We are grateful to the writers and reviewers who assist us in our information production. A list of who this includes may be viewed on our website: www.smauk.org.uk/our-writers-and-reviewers-panel or requested from supportservices@smauk.org.uk

Whilst every effort is made to ensure that the information in this publication is complete, correct and up to date, this cannot be guaranteed and Spinal Muscular Atrophy UK shall not be liable whatsoever for any damages incurred as a result of its use. SMA UK does not necessarily endorse the services provided by the organisations listed in our information sheets.

If you have any feedback about this information, please do let us know at supportservices@smauk.org.uk