Spinal Muscular Atrophy
Overview
Spinal muscular atrophy (SMA) is a group of inherited conditions that affects the motor neurons of the spinal cord causing muscle weakness. Symptoms include difficulty crawling, walking, breathing, swallowing, and controlling the head and neck. There are several types of SMA; classification is based on the severity of the condition and the age at which symptoms begin. Early detection and treatment are most effective when started early.The long-term outlook varies significantly based on the type, symptoms, and response to treatment. The more severe types of SMA are associated with a shortened lifespan. Newer therapies may improve survival. In general, infants with SMA type I die in early childhood. Those affected by SMA type II live into adolescence and early adulthood. Most people with type III have a normal lifespan but are more susceptible to respiratory infections. SMA type IV is associated with a normal life expectancy.
Incidence
Approximately 1 in 12,500 [Verhaart: 2017]Prenatal Testing
DNA testing by amniocentesis or chorionic villus sampling (CVS) if both disease causing mutations of an affected family member have been identifiedClinical Characteristics
Newborns with SMA will usually be asymptomatic. Those with Type 1 may develop apparent hypotonia within weeks of birth. Newborns with the rare Type 0 will be severely hypotonic at birth and have contractures, swallowing problems, and respiratory failure.Primary Care Management
Upon Notification of the + Screen
- Contact pediatric neurology to coordinate URGENT evaluation and additional testing; Pediatric Neurology (see NW providers [0]). FDA-approved treatments are available and should be started within days of identification.
- Contact family regarding the need for evaluation and additional testing.
Specialty Care Collaboration
Initial consultation with Pediatric Neurology (see NW providers [0]) and ongoing collaboration if the child is affected. Genetic Testing and Counseling (see NW providers [2]) for the family.Resources
Information & Support
For Professionals
Spinal Muscular Atrophy (GeneReviews)
An expert-authored, peer-reviewed, current disease description that applies genetic testing to diagnosis and management information;
U.S. National Library of Medicine.
Spinal Muscular Atrophy Type I (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance
in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine
Spinal Muscular Atrophy Type II (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance
in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine
Spinal Muscular Atrophy Type III (OMIM)
Information about clinical features, diagnosis, management, and molecular and population genetics; Online Mendelian Inheritance
in Man, authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine
For Parents and Patients
Genetic Conditions: Spinal Muscular Atrophy (MedlinePlus)
Excellent, detailed review of condition for patients and families; National Library of Medicine and National Institutes of
Health.
Baby's First Test (Genetic Alliance)
Clearinghouse for local, state, and national newborn screening education, programs, policies, and resources. Also, provides
many ways for people to connect and share their viewpoints and questions about newborn screening; supported by the U.S. Department
of Health and Human Services.
Services for Patients & Families Nationwide (NW)
Service Categories | # of providers* in: | NW | Partner states (6) (show) | | ID | MT | NM | NV | RI | UT | |
---|---|---|---|---|---|---|---|---|---|---|---|
Genetic Testing and Counseling | 2 | 6 | 8 | 59 | 20 | 4 | 12 | ||||
Newborn Screening Services | 1 | 22 | 4 | 2 | 2 | 1 | 3 | ||||
Pediatric Genetics | 1 | 3 | 7 | 4 | 5 | 4 | 7 | ||||
Pediatric Neurology | 1 | 16 | 31 | 6 | 15 | 6 |
For services not listed above, browse our Services categories or search our database.
* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.
Page Bibliography
Verhaart IEC, Robertson A, Wilson IJ, Aartsma-Rus A, Cameron S, Jones CC, Cook SF, Lochmüller H.
Prevalence, incidence and carrier frequency of 5q-linked spinal muscular atrophy - a literature review.
Orphanet J Rare Dis.
2017;12(1):124.
PubMed abstract / Full Text