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]

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]

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]

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]

• Falling

  An older child might fall more often than kids of the same age or have trouble lifting things. Kids with SMA can develop scoliosis (a curved spine) if the back muscles are weak. [kidshealth.org]

  Most will show difficulty walking at some stage, though toddlers and children will fall frequently, have difficulty getting up from a sitting position, or be unable to run, whereas others may be diagnosed in late adolescence or early adulthood. [smaaustralia.org.au]

  The patients learn to walk successfully, but tend to fall frequently. If your child has this problem, you will notice that they have difficulties walking down and up the stairs. [muscleatrophy.net]

  Balance can be a problem, causing falls, sometimes assistance in getting up is needed. General muscle weakness has an impact on daily living. [checkorphan.org]

• Crying

  They include severe weakness or 'floppiness', poor head control, weak cry and cough, and difficulty with swallowing and feeding. SMA type 2: This develops within the first three years of life. [rch.org.au]

  Hypotonia (“floppy” baby) “Frog legs” Feeding difficulties Weak sucking Tongue fluttering Weak cry Lack of motor development or delay in motor milestones Lack of reflexes Belly Breathing Small muscles Proximal muscle weakness What Is the Treatment for [luriechildrens.org]

  In infants, the most common demographic affected, this classically manifests as difficulties sitting and rolling, assuming a frog-leg position, a weak cry, and increased respiratory effort with paradoxical breathing 1,3. [radiopaedia.org]

  Babies typically have generalized muscle weakness, a weak cry, and breathing distress. They often have difficulty swallowing and sucking and don't reach the developmental milestone of being able to sit up unassisted. [mda.org]

  […] cramps and twitching in arms, shoulders and tongue Difficulty keeping posture Slurred speech Hoarseness or decreased volume when speaking Aspiration or choking when eating Emotional and cognitive symptoms specific to ALS onset: Involuntary laughing or crying [thehumanthebody.com]

• Anemia

  […] syndrome, Shwachman-Bodian syndrome, Pancreatic Insufficiency and congenital lipomatosis of pancreas,Metaphyseal chondrodysplasia (Shwachman-Diamondtype), SDS Sichelzellenanämie ( 2 Files ) Erkrankung: Sichelzellenanämie ICD 10: D57.1 Synonyme: Sickle Cell Anemia [orphananesthesia.eu]

  Consider labs to evaluate for nutritional inadequacies, carnitine deficiency, hypercalcemia, and iron deficiency anemia. A urinalysis will detect urinary tract infection, etc. [medicalhomeportal.org]

• Weight Loss

  Once symptoms of the disease present themselves, patients generally suffer from generalized weakness, limpness, difficulty walking, problems with breathing, trouble swallowing and weight loss from muscle atrophy. [sandiegouniontribune.com]

• Fasciculation of the Tongue

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

  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]

• 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]

  atrophy SMN2 gene copy numbers are variable in individuals with spinal muscular atrophy. [togetherinsma-hcp.com]

  (Clinical, electromyographic and pathological study). 56 SPIRA R 13990174 1963 44 [Apropos of heredofamilial juvenile muscular atrophy]. 56 HAUSMANOWA-PETRUSEWICZ I...DOBOSZ I 13961045 1962 45 Heredofamilial juvenile muscular atrophy simulating muscular [malacards.org]

  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]

• 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]

  […] have weak muscles, minimal muscle tone, and feeding and breathing problems. [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]

  The similarities between the two conditions are many, including age of onset, proximal muscle weakness, heredofamilial, male preponderance, rasied muscle enzymes and normal nerve conduction studies. [scholarbank.nus.sg]

• Proximal Muscle Weakness

  The similarities between the two conditions are many, including age of onset, proximal muscle weakness, heredofamilial, male preponderance, rasied muscle enzymes and normal nerve conduction studies. [scholarbank.nus.sg]

  Salient Features 4-8 Presents as lower motor neuron type of weakness, mainly affects proximal muscles. Facial and extraocular muscles are usually not affected. Classified into 4 types based on onset and progression of the condition. [genetics4medics.com]

  Chapter First Online: 27 June 2014 Abstract Spinal muscular atrophy type 3 (SMA3), or Kugelberg-Welander disease, is a relatively mild form of spinal muscular atrophy characterized by proximal muscle weakness and hypotonia caused by the degeneration of [link.springer.com]

  Proximal muscle weakness, especially of the lower extremities, and muscular atrophy were the predominant clinical features. Elevated serum creatine kinase levels were noted in four female and 12 male patients, and… CONTINUE READING [semanticscholar.org]

  Proximal muscle weakness, especially of the lower extremities, and muscular atrophy were the predominant clinical features. [pubmed.ncbi.nlm.nih.gov]

• 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]

  […] atrophy Initial symptoms may include: Tremor of the hands Muscle cramps when performing physical activities Muscle twitches and weakness of limb muscles As the condition progresses: Weakness of the face and tongue muscles which may cause difficulties [thehumanthebody.com]

  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]

• Leg Weakness

  People with this condition may experience: Leg weakness, especially in the thigh muscles An unsteady gait Difficulty standing from a seated position Trouble climbing stairs Causes and Risk Factors Although spinal muscle atrophy has many forms, they are [cedars-sinai.edu]

  However, a small number of people with more extensive spina bifida occulta may have some of the following symptoms: Foot deformity Leg weakness, numbness, or clumsiness Bladder or bowel dysfunction Hand weakness or numbness These symptoms can be the result [columbiaspine.org]

  However, one in 1,000 individuals will have an occult structural finding that leads to neurological deficits or disabilities as bowel or bladder dysfunction, back pain, leg weakness or scoliosis. [aans.org]

• Presentation at Age >18 Months

  The range of life expectancy is broad at 10 to 40 years. • Children with type 3 SMA (Kugelberg-Welander disease) and those with type 4 SMA present after age 18 months and after 5 years, respectively. [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]

• Absent Deep Tendon Reflexes

  Signs of motor neuron disease such as muscle weakness, muscle atrophy, fasciculations, and reduced or absent deep tendon reflexes can be seen. [medlink.com]

• Areflexia

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

  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]

  Decreased bladder wall compliance is associated with areflexia of the detrusor. [emedicine.medscape.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]

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]

[…] noted, but muscle wasting of the affected musculature is more prominent Patients may have a positive Gowers sign and a waddling gait Approximately one third of patients have facial and masseter muscle weakness Sensory examination findings are normal Workup [emedicine.medscape.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]

Detecting the condition at this stage may allow for treatment before symptoms appear. There is currently no cure for SMA and no way to prevent it, as it is an inherited condition. However, treatment can help a person live a full life. [medicalnewstoday.com]

[…] or walking frame physiotherapy treatments for scoliosis. [healthdirect.gov.au]

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]

AVXS-101) which hold promise in improving the quality of life and prognosis of these patients 7-9. [radiopaedia.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]

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

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]

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

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]

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]

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]

The individual may have scoliosis or contractures, a shortening of the muscles or tendons, which can prevent the joints from moving freely. [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]

Back muscle weakness : Bracing has been found to be a good source of support in children with SMA, especially in preventing scoliosis. Spinal fusion may also become necessary. [curascriptsd.com]

Those affected by the disorder can work with their health care providers to manage SMA symptoms and prevent complications, which can contribute to quality of life. [hopkinsmedicine.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.