The incidence is about 60% to present with the most severe form, which presents before 6 months of age, in what we call in the natural history type 1 SMA. But there are milder forms that could present at later times of life as well. [ajmc.com]

Type 1 Symptoms Present by 6 Months The most severe form of the disease, Type 1 SMA symptoms are present during infancy. Affected children will not acquire the power, the strength, and the endurance to sit up independently, to crawl, or to walk. [addygracefoundation.com]

Also known as Werdnig-Hoffmann Disease -Weakness present at birth or prior to 4 months of age -Cranial nerve involvement may or may not be seen -Respiratory problems often with accessory muscles present for breathing -Do not transition away from belly [quizlet.com]

Severity of SMA is related to the number of SMN2 copies present. SMA type 1 patients usually have 2 copies of SMN2, while type IV patients usually have 3-4 copies. Inheritance : Autosomal recessive. [genetics4medics.com]

There are four main types of SMA, which include the following: Type 1: Symptoms present by 6 months. This is the most severe form of the disease and present during infancy. [curascriptsd.com]

• Death in Infancy

  It is one of the most prevalent genetic disorders affecting young children and a major cause of death in infancy. SMA can strike children at any age. [hopkinsmedicine.org]

  Spinal muscular atrophy (SMA) is the leading genetic cause of death in infancy, with an estimated incidence of 1 in 6000 to 1 in 10 000 live births.1-4 Most patients have a homozygous SMN1 deletion of exon 7, making diagnostic confirmation readily available [jamanetwork.com]

• Fasciculation of the Tongue

  They will see if the muscles are floppy or flaccid, to check for deep tendon reflexes and muscle fasciculation of the tongue muscle. [medicalnewstoday.com]

  These have included difficulty chewing and swallowing, sternocleidomastoid and trapezius weakness and atrophy, and fasciculations of the tongue. [healio.com]

• Muscular Atrophy

  TABLE 6 U.S. spinal muscular atrophy treatment market, by disease type, 2015 - 2025 (USD Million) TABLE 7 U.S. spinal muscular atrophy treatment market, by treatment, 2015 - 2025 (USD Million) TABLE 8 U.S. spinal muscular atrophy treatment market, by [giikorea.co.kr]

  Not yet recruiting Click for more information Spinraza in Adult Spinal Muscular Atrophy 17th October 2018 Conditions : Spinal Muscular Atrophy; Spinal Muscular Atrophy Type II; Spinal Muscular Atrophy Type 3 Intervention : Other: Observational study [treat-nmd.eu]

  atrophy patients. 6 Bussaglia E...Baiget M 7581461 1995 32 Pulmonary function in spinal muscular atrophy. 56 Samaha FJ...Zimmerman L 7930415 1994 33 Paternal isodisomy for chromosome 5 in a child with spinal muscular atrophy. 56 Brzustowicz LM...Koenigsberger [malacards.org]

  Juvenile spinal muscular atrophy or type 3 muscular atrophy is a milder form of spinal muscular atrophy that typically manifests between 18 months of age and early adolescence. [kidbones.net]

• Muscle Weakness

  Symptoms include generalized weakness and muscle wasting with muscle twitches common, atrophy of distal leg muscles, thigh muscle weakness, distal arm muscle weakness, impaired vibratory sense, variable diminished leg deep tendon reflexes, no cortical [smaaustralia.org.au]

  Swallowing muscle weakness : Infants with swallowing or sucking weakness can be fed with a gastrostomy tube. Back muscle weakness : Bracing has been found to be a good source of support in children with SMA, especially in preventing scoliosis. [curascriptsd.com]

  Common symptoms include: muscle weakness and twitching difficulty breathing and swallowing changes in the shape of the limbs, spine, and chest due to muscle weakness difficulty standing, walking, and possibly sitting At birth, infants with SMA type 1 [medicalnewstoday.com]

  It is caused by a loss of specialized nerve cells, called lower motor neurons, leading to muscle weakness and muscle cell death. [smanewstoday.com]

  Have muscle weakness which progresses very slowly Are very bright Face problems in balancing leading to falls Experience no change in life expectancy Signs and symptoms of juvenile spinal muscular atrophy include muscle weakness where the legs are much [kidbones.net]

• Muscle Twitch

  Symptoms include generalized weakness and muscle wasting with muscle twitches common, atrophy of distal leg muscles, thigh muscle weakness, distal arm muscle weakness, impaired vibratory sense, variable diminished leg deep tendon reflexes, no cortical [smaaustralia.org.au]

  People with type 4 may experience muscle twitches, muscle weakness and difficulty walking. They don’t usually have problems with breathing or swallowing and they usually have a normal life expectancy. What causes SMA? SMA is a genetic condition. [healthdirect.gov.au]

  Other symptoms include: Muscle atrophy Muscle weakness Areflexia Trouble Breathing Thin muscle mass Trouble eating or swallowing Lack of head and neck control Involuntary facial twitching Atrophic muscle changes Muscle twitching Sensory neuropathies Difficulty [stemcellthailand.org]

  twitches and weakness of limb muscles As the condition progresses: Weakness of the face and tongue muscles which may cause difficulties when swallowing and speaking Recurring pneumonia Some patients also develop enlarged male breasts (gynaecomastia), [thehumanthebody.com]

• Muscle Hypotonia

  Children can ambulate, but they have proximal muscle weakness and various degrees of muscle hypotonia and wasting. The lower extremities are often more severely affected than the upper extremities. [ispub.com]

• Type A Personality

  Meanwhile, Udani said the disease is genetically inherited and doesn’t selectively affect any particular type of person. “(The) causes are all genetic,” he said. “As of now, there is no known prevention.” [sandiegouniontribune.com]

  SMA is a genetic condition that can affect children or adults, depending on the type. A person’s outlook will depend on the severity of the symptoms. [medicalnewstoday.com]

• Presentation at Age >18 Months

  • Children with type 3 SMA (Kugelberg-Welander disease) and those with type 4 SMA present after age 18 months and after 5 years, respectively. These children usually meet gross motor milestones (sitting, standing, and walking). [neurologytimes.com]

  Kugelberg Welander spinal muscular atrophy (also known as Wohlfart-Kugelberg-Welander syndrome or mild SMA) is a milder form of SMA, with symptoms typically presenting after age 18 months. [1, 2, 3] SMAs were first described in the 1890s, by Guido Werdnig [emedicine.medscape.com]

• Hand Tremor

  They have delayed motor (physical) milestones, poor weight gain, weak cough, hand tremors, contractures (fixed deformities of joints) and scoliosis (curved spine). [rch.org.au]

  Muscle cramps, facial fasciculations, hand tremor. Associated with type 2 diabetes and infertility. [patient.info]

  He also had a hand tremor, sometimes visible, sometimes just felt, sometimes not evident at all, and we associated this with emotional moments – excitement, upset. [doofercall.blogspot.com]

• Limb Weakness

  Department of Neurology College of Medicine Hanyang University Abstract Wohlfart et al and then Kugelberg and Welander were concerned with patients suffering from proximal limb weakness that resembled muscular dystrophy, but the muscle biopsy and EMG [jkna.org]

  As the disease progresses patients may notice limb weakness starting in the pelvis or shoulders, or weakness of the facial and tongue muscles. Symptoms of SMA-LED often develop in infancy or early childhood. [cedars-sinai.edu]

• Hyporeflexia

  Patients have diffuse, symmetric muscle weakness that is greater proximally and in the lower limbs; hyporeflexia or areflexia; and progressive respiratory insufficiency. [neurologytimes.com]

• Flail Arm

  Arm ALS; Progressive Muscular Atrophy; Monomelic Amyotrophy; Motor Neuron Disease; Asymptomatic ALS Gene Carriers; Healthy Controls Intervention : Sponsors : Johns Hopkins University; Massachusetts General Hospital; Emory University; Ohio State University [treat-nmd.eu]

Initial diagnostic workup should comprise serum creatine kinase (CK) levels, electromyography (EMG) and nerve conduction studies, while confirmation can be obtained by using molecular and genetic tests that will detect homozygous deletion of SMN1. [symptoma.com]

TABLE 6 U.S. spinal muscular atrophy treatment market, by disease type, 2015 - 2025 (USD Million) TABLE 7 U.S. spinal muscular atrophy treatment market, by treatment, 2015 - 2025 (USD Million) TABLE 8 U.S. spinal muscular atrophy treatment market, by [giikorea.co.kr]

“Critically, the Working Group notes that the loss of even a small number of motor neurons is unacceptable when effective treatment is available, as this loss cannot be reversed after onset but can be prevented with earlier treatment.” [neurologylive.com]

The treatment will now be being assessed for all types of SMA, with Spinraza… READ ARTICLE Biogen and Ionis Pharmaceuticals have announced that they have entered into a new collaboration to identify new antisense oligonucleotide drugs for the treatment [smatrust.org]

TREATMENT PRECAUTION Please note that not all cases will qualify for treatment of Spinal Muscular Atrophy using enhanced neural stem cells. [stemcellthailand.org]

However the prognosis is very good. The person with Type III may show difficulty with walking and/or getting up from a sitting or bent over position & negotiating stairs. [checkorphan.org]

SMA type 3 Prognosis and Life Expectancy The prognosis of SMA type 3 varies from one patient to another. However, the course is slowly progressive. [muscleatrophy.net]

Prognosis A wheelchair may be required during childhood for some patients (more commonly those with SMA3a), whilst others retain the ability to walk into adulthood (more commonly those with SMA3b). [orpha.net]

Etiology As for other forms of SMA, SMA3 is primarily caused by deletions in the SMN1 gene (5q12.2-q13.3) encoding the SMN (survival motor neuron) protein. [orpha.net]

Etiology As for other forms of SMA, SMA3 is primarily caused by deletions in the SMN1gene (5q12.2-q13.3) encoding the SMN (survival motor neuron) protein. [rarediseases.info.nih.gov]

Overall, tissue ischemia from pressure necrosis is the most common etiology. [emedicine.medscape.com]

Etiology, pathogenesis and prevention of neural tube defects. Congenit Anom. (Kyoto). 2006;46:55-67. Xiao CG. [rarediseases.org]

Summary Epidemiology Prevalence is estimated at around 1/375,000. Clinical description The disease manifests after 12 months of age (usually between childhood and adolescence), after ambulation has been acquired. [orpha.net]

Epidemiology Prevalence is estimated at around 1/375,000. Clinical description The disease manifests after 12 months of age (usually between childhood and adolescence), after ambulation has been acquired. [rarediseases.info.nih.gov]

The book also provides updated epidemiologic and statistical data throughout and includes a section on biostatistics in physical medicine and rehabilitation. [books.google.de]

The epidemiologic burden of SMA is not equally divided over the subtypes. [ojrd.biomedcentral.com]

Related Medscape Reference topics: Focal Muscular Atrophies Spinal Muscle Atrophy Spinal Muscular Atrophy Related Medscape resource: Resource Center Spinal Disorders Pathophysiology Spinal muscular atrophy (SMA) is caused by successive motor unit degeneration [emedicine.medscape.com]

Pathophysiology Spinal muscular atrophy (SMA) types I-III Inheritance is autosomal recessive. Affected individuals have two copies of the altered gene. Those who carry one copy are usually unaffected carriers. [patient.info]

SMA cannot be prevented, but prospective parents can request genetic testing if they may be carriers. Types There are different types of SMA. [medicalnewstoday.com]

Scientists hope to characterize the genes, study gene function and disease course, and find ways to prevent, treat, and, ultimately, cure these diseases. [christopherreeve.org]

Prevention - Spinal muscular atrophy- type 3 Not supplied. Diagnosis - Spinal muscular atrophy- type 3 Not supplied. [checkorphan.org]

See Patient Stories » At Nemours, we’re actively researching new approaches for childhood disease prevention, diagnosis and treatment. Learn more about your child’s medical condition from the experts at Nemours’ KidsHealth. [nemours.org]

Spinal muscular atrophies (SMAs) are neurodegenerative disorders caused by mutations in the survival motor neuron 1 (SMN1) gene. Progressive destruction of neurons located in the anterior horn of the spinal cord develops as a result of homozygous deletion of specific segments (exon 7) on SMN1 through autosomal recessive patterns of inheritance [1]. SMAs are estimated to occur in 1 every 10,000 births and type 3 (known as Kugelberg-Welander disease) comprises about 30% of all cases [1] [2]. The onset of symptoms ranges between 18 months - 30 years of age, and further classification divides type 3 into type 3a (onset between 18 months and 3 years) and 3b (onset between 3-30 years) [1]. Progressive weakness of proximal limbs, more commonly involving the legs than arms, is a typical finding that may be severe enough to require use of a wheelchair or walking aids [3]. Respiratory muscle weakness, which predisposes the majority of patients suffering from type 1 or type 2 to nocturnal hypoventilation, recurrent infections and respiratory failure, as well as swallowing difficulties and scoliosis, are usually absent in type 3 individual, and life expectancy is rarely shortened by complications of the disease [1] [3] [4]. Additional signs of SMA type 3 are joint pain and preserved cognitive skills [3]. Initial diagnostic workup should comprise serum creatine kinase (CK) levels, electromyography (EMG) and nerve conduction studies, while confirmation can be obtained by using molecular and genetic tests that will detect homozygous deletion of SMN1 [4] [5]. Treatment focuses on symptomatic measures, mainly to provide support when walking or experiencing symptoms of weakness, while more severe measures (insertion of feeding tubes or assisted ventilation) are rarely necessary, and are reserved for more severe forms of SMA (types 1 and 2) [1] [4] [5].

1. Arnold WD, Kassar D, Kissel JT. Spinal Muscular Atrophy: Diagnosis and Management in a New Therapeutic Era. Muscle Nerve. 2015;51(2):157-167.
2. Sugarman EA, Nagan N, Zhu H, et al. Pan-ethnic carrier screening and prenatal diagnosis for spinal muscular atrophy: clinical laboratory analysis of >72 400 specimens. Eur J Hum Genet. 2012;20(1):27-32.
3. Kolb SJ, Kissel JT. Spinal Muscular Atrophy. Neurol Clin. 2015;33(4):831-846.
4. Wang CH, Finkel RS, Bertini ES, et al. Consensus statement for standard of care in spinal muscular atrophy. J Child Neurol. 2007;22(8):1027-1049.
5. Prior TW. Spinal muscular atrophy diagnostics. J Child Neurol. 2007;22(8):952-956.