Rarer Forms of SMA

SMA is the name given to a number of genetically distinct conditions which all result in muscle weakness. There is a great variation in the severity and impact they have. The more common form of SMA is broadly known as 5q SMA (Types 1, 2, 3 and 4).

These pages provide information about some other rarer forms of SMA. For some of these, the information is very limited.

The Inheritance Patterns of Some Rarer Forms of SMA

This guide tells you how genetic conditions are inherited. It identifies the different inheritance patterns for the rarer forms of SMA (see below). It includes information about the chances of children being affected.

Distal Spinal Muscular Atrophy type V (DSMA-V)

A child or adult may be diagnosed with this very rare condition. There is very little information about it.

Spinal and Bulbar Muscular Atrophy (SBMA) – Kennedy’s Disease

This is an adult onset form of SMA. We provide some information about the condition with links to further information and sources of support.

SMA with Lower Extremity Predominance (SMA-LED)

A child or adult may be diagnosed with this very rare condition. There is very little information about it.

SMA with Progressive Myoclonic Epilepsy (SMA-PME)

A child may be diagnosed with this very rare condition. There is very little information about it.

Spinal Muscular Atrophy with Respiratory Distress 1 (SMARD1)

This is a childhood onset form of SMA. You can find information about the condition on these pages. There are also some families’ experiences of when their child has been diagnosed with SMARD1.

X-Linked Spinal Muscular Atrophy

A child or adult may be diagnosed with this very rare condition. There is very little information about it.

Research into some Rarer Forms of Spinal Muscular Atrophy

This is very limited due to the small numbers of individuals affected by these conditions. No drug treatments have so far been approved for any of them. These pages give an overview of research into three of the very rare forms of SMA.

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