SCHN leading the way in the treatment of Spinal Muscular Atrophy
The Sydney Children’s Hospitals Network is leading the way in progressing treatment of Spinal Muscular Atrophy (SMA), offering SMA type 1 patients access to a novel new therapy as part of an Expanded Access Program.
SMA is a paediatric disorder similar to adult motor neuron disease, which affects the motor neurons of the spinal cord, causing muscle weakness and wasting. SMA causes the premature death of affected children, in the most severe cases before two years of age. In the past the treatment of SMA has been symptomatic, based on comfort measures and management of complications of weakness, feeding and breathing difficulties. There has been no specific treatment for SMA.
However the landscape for SMA patients is radically changing with the identification of a novel therapeutic agent, Nusinersen, which has been shown to improve motor development in babies and children with SMA types 1 and 2. An Extended Access Program (EAP) for SMA type 1 means that infants with this diagnosis will be able to access Nusinersen– free of charge to the patient, hospital or state – before it goes through the full process of regulatory approval in Australia. That regulatory process could take months or years.
Nusinersen is showing improvements in strength and motor function in babies and children with SMA types 1 and 2. Results of some studies are still pending but the information available to date suggests that this medication is more effective when administered early in the disease course. Ongoing research will provide more information regarding the long-term benefits of this drug.
Several SMA Type 1 patients have already been treated with Nusinersen at Sydney Children’s Hospital, Randwick and The Children’s Hospital at Westmead with clinicians seeing promising results.
Early treatment is especially critical in babies with SMA type 1. Clinicians across Sydney Children’s Hospitals Network are calling on parents, early childhood nurses, allied health practitioners, GPs and any other individuals that work with children to be aware of SMA. If you are concerned a child may have SMA, please refer patients urgently to neuromuscular clinics for review.
LEARN MORE ABOUT SMA
What is Spinal Muscular Atrophy (SMA)?
Although a rare disease, SMA is the leading genetic cause of death affecting 1 in 6000 children.
SMA is a paediatric disorder similar to adult motor neuron disease, which affects the motor neurons of the spinal cord, causing muscle weakness and wasting. SMA causes the premature death of affected children, in the most severe cases before two years of age.
SMA is a recessive disorder caused by abnormalities in the SMN1 (Survival Motor Neuron 1) gene. If the SMN1 gene has reduced function, motor neurons in the spinal cord and brainstem die prematurely; this process starts before birth, so some children are symptomatic in the first few weeks or months of life.
How many types of SMA are there?
SMA is a very complex disease, affecting each child differently. There are three common types of SMA, as outlined here:
Type I (severe) (formerly known as Werdnig-Hoffman disease)
Onset: 0-6 months
Highest level of motor function: Never sits
Life expectancy: <2 years
Typical features: Severe weakness in “floppy” babies, poor head control, weak cry and cough, difficulty with swallowing and handling of oral secretions, “bell shaped” chest from use of accessory muscles in breathing, early morbidity due to respiratory insufficiency and aspiration pneumonia
Type II (intermediate)
Onset: 7-18 months
Highest level of motor function: Never stands
Life expectancy: >2 years
Typical features: Delayed motor milestones, poor weight gain, weak cough, hand tremors, contractures and scoliosis
Type III (mild) (formerly known as Kugelberg-Welander disease)
Onset: >18 months
Highest level of motor function: Stands and walks
Life expectancy: Adult
Typical features: Variable muscle weakness, cramps, joint overuse syndromes
How do clinicians diagnose SMA?
The diagnostic process in SMA generally begins with parents, Maternal Child Health Nurses or the local doctor raising concerns about floppiness, low muscle tone or weakness in babies and small children. As these symptoms can be benign, and can relate to many other conditions, they are often dismissed or monitored for further developments.
A single blood test can confirm if a child has the mutation in the SMN gene that causes SMA.
What are the symptoms of SMA?
* Poor head control
* Absent deep tendon reflexes
* Delayed motor milestones in the first year of life
Possible cases of SMA1 should be referred urgently to the neuromuscular clinics in each state; contact numbers are below.
In New South Wales, families can contact Margot Morrison or Sandra Holland, Neuromuscular Nurse Coordinators (Margot.Morrison@health.nsw.gov.au; Sandra.Holland@health.nsw.gov.au) or Michelle Farrar (Michelle.Farrar@health.nsw.gov.au)
In Queensland, families can contact Dr Anita Cairns or Kate Munro, Neuromuscular Clinical Nurse Consultant via CHQ-Neuromuscular@health.qld.gov.au