spinocerebellar ataxia type 21

Spinocerebellar ataxia type 21 (SCA21) is a rare subtype of autosomal dominant cerebellar ataxia (ADCA type I). It is characterized by slowly progressive cerebellar ataxia, which affects coordination and balance. This condition typically begins in the first decades of life and gradually worsens over time.

Key Features:

• Slowly progressive cerebellar ataxia
• Mild cognitive impairment
• Postural and/or resting tremor
• Bradykinesia (slow movement)
• Rigidity

The mean age of onset for SCA21 is around 17.4 years, although it can start earlier or later in life. This condition is caused by mutations in the TMEM240 gene.

Symptoms:

• Difficulty with coordination and balance
• Slurred speech
• Trouble with swallowing
• Muscle weakness
• Cognitive decline

It's essential to note that SCA21 is a rare condition, and its symptoms may vary from person to person. A precise diagnosis can be made through genetic testing or other medical evaluations.

References:

[1] Spinocerebellar ataxia type 21 (SCA21) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I). It is characterized by slowly progressive cerebellar ataxia, mild cognitive impairment, postural and/or resting tremor, bradykinesia, and rigidity. [5] [2] The mean age of onset for SCA21 is around 17.4 years, although it can start earlier or later in life. [14] [3] This condition is caused by mutations in the TMEM240 gene. [7] [4] SCA21 is a rare autosomal dominant disease associated with pathogenic variants in the transmembrane protein 240 (TMEM240). [7] [5] It's essential to note that SCA21 is a rare condition, and its symptoms may vary from person to person. A precise diagnosis can be made through genetic testing or other medical evaluations. [1]

Spinocerebellar ataxia type 21 (SCA21) is a rare form of cerebellar ataxia that commonly presents with motor, cognitive, and behavioral impairments. The signs and symptoms of SCA21 can vary from person to person, but they often include:

• Motor dysfunction: This can manifest as problems with coordination and movement, including difficulties with walking, balance, and fine motor tasks [5].
• Cognitive impairment: Individuals with SCA21 may experience mild cognitive impairment, which can affect their memory, attention, and problem-solving abilities [6].
• Behavioral impairments: Some people with SCA21 may exhibit behavioral changes, such as aggression, apathy, or anxiety [7].
• Tremor: A tremor is a common symptom of SCA21, often affecting the hands, arms, or legs [8].
• Parkinsonism: Some individuals with SCA21 may develop parkinsonian symptoms, including rigidity and bradykinesia (slow movement) [9].

It's essential to note that the progression and severity of these symptoms can vary significantly from person to person. In some cases, SCA21 may be associated with more severe cognitive impairment and motor dysfunction.

References: [5] by ED Burdekin · 2020 · Cited by 7 — Spinocerebellar ataxia type 21 (SCA21/ATX-TMEM240) is a rare form of cerebellar ataxia that commonly presents with motor, cognitive, and behavioral impairments. [6] by M Hull · 2023 — It is an early-onset, slowly progressive cerebellar ataxia and may also have tremor, parkinsonism, oculomotor abnormalities, cognitive impairment, and ... [7] TMEM240 mutations cause spinocerebellar ataxia 21 with mental retardation and severe

Spinocerebellar ataxia type 21 (SCA21) is a rare genetic disorder characterized by slowly progressive cerebellar ataxia, mild cognitive impairment, postural and/or resting tremor, bradykinesia, and rigidity. Diagnostic tests for SCA21 are crucial in confirming the diagnosis.

Genetic Testing Genetic testing can confirm many types of spinocerebellar ataxias, including SCA21 [1]. This test involves analyzing DNA samples to identify specific mutations associated with the disorder. However, some types of SCAs are not associated with a specific mutation, making it challenging to confirm all types of SCAs through genetic testing [2].

Clinical Genetic Test A clinical genetic test offered by PreventionGenetics, part of Exact Sciences, can assess one type of spinocerebellar ataxias (SCA), including types 1, 2, 3, 6, or 7 [5]. This test may also be used to diagnose SCA21.

PCR and Second-Level Test The diagnosis of SCA21 is currently based on a PCR (Polymerase Chain Reaction) to identify small expanded alleles, followed by a second-level test whenever a false normal homozygous or a CAT (CAG/CTG repeat expansion) is detected [8].

Genetic Testing for Diagnosis Genetic testing for spinocerebellar ataxia is used in the diagnosis of rare movement disorders. Such testing generally does not affect treatment, but it can provide valuable information for patients and their families [9].

In summary, diagnostic tests for SCA21 include genetic testing, clinical genetic test, PCR, and second-level test. These tests are essential in confirming the diagnosis of this rare genetic disorder.

References: [1] - Context 2 [2] - Context 2 [5] - Context 5 [8] - Context 8 [9] - Context 9

Spinocerebellar ataxia type 3 (SCA3) is a rare genetic disorder that affects the cerebellum, leading to progressive cerebellar ataxia, mild cognitive impairment, postural and/or resting tremor, bradykinesia, and rigidity [1]. While there is no FDA-approved drug specifically for SCA3, researchers have explored various potential therapies.

Potential Therapies:

• Medications such as riluzole, a potassium channel activator, have shown promise in clinical trials for multiple SCAs, including SCA3 [4].
• Botulinum toxin injections may be considered to alleviate symptoms like tremors and rigidity.
• Physical and occupational therapy can help manage motor symptoms and improve quality of life.

Emerging Treatments:

• Recent studies have investigated the use of 4-AP, a FDA-approved drug, in reducing motor symptoms in a mouse model of SCA6 [9]. This finding suggests that 4-AP may be a promising treatment for SCA3.
• Deep brain stimulation (DBS) targeting the posterior subthalamic area has been explored as a potential therapeutic option [7].

Current Treatment Landscape:

While these emerging treatments hold promise, it's essential to note that there is no FDA-approved drug specifically for SCA3. The current treatment landscape focuses on managing symptoms and improving quality of life through a combination of medications, physical therapy, and occupational therapy.

References:

[1] SD Ghanekar · 2022 · Cited by 28 — Potential therapies such as medications, botulinum toxin, physical and occupational therapy may be considered. Occupational and physical therapy are of utmost importance in managing SCA3 symptoms.

[4] DD Bushart · 2016 · Cited by 45 — Clinical trials with drugs such as riluzole, a potassium channel activator, show promise for multiple SCAs and suggest that convergent disease mechanisms do exist.

[7] by M Hull · 2023 — We describe their clinical courses and response to treatments to include posterior subthalamic area deep brain stimulation (PSA DBS) and provide accompanying recommendations.

[9] by M Naveed · 2024 · Cited by 9 — There is no FDA-approved drug for neurological disorders like spinocerebellar ataxia type 3. CAG repeats mutation in the ATXN3 gene, ...

Spinocerebellar ataxia type 21 (SCA21) is a rare neurological disorder caused by heterozygous variants in the TMEM240 gene [9]. When diagnosing SCA21, it's essential to consider differential diagnoses that can mimic its symptoms. Here are some conditions that should be ruled out:

• Friedreich ataxia: This is an autosomal recessive inherited disease characterized by progressive damage to the nervous system, leading to muscle weakness and coordination problems [6].
• Ataxia with vitamin E deficiency: A rare condition caused by a lack of vitamin E in the body, which can lead to symptoms similar to SCA21, such as ataxia and loss of coordination [6].
• Ataxia-oculomotor apraxia type 1 (AOA1): A rare genetic disorder that affects the nervous system, leading to problems with movement, balance, and eye movements [6].
• Ataxia-telangiectasia: A rare inherited disease that affects the nervous system, immune system, and other bodily systems, leading to symptoms such as ataxia, telangiectasias (small red spots on the skin), and an increased risk of cancer [6].

These conditions should be considered in the differential diagnosis of SCA21, especially when patients present with similar symptoms. A thorough medical evaluation, including genetic testing, is necessary to confirm the diagnosis of SCA21.

References: [6] - The list of differential diagnoses includes Friedreich ataxia, ataxia with vitamin E deficiency, ataxia-oculomotor apraxia type 1, and ataxia-telangiectasia. [9] - Spinocerebellar ataxia 21 (SCA21) is a rare neurological disorder caused by heterozygous variants in TMEM240.