autosomal recessive spinocerebellar ataxia 7

Autosomal Recessive Spinocerebellar Ataxia 7 (SCAR7)

Autosomal recessive spinocerebellar ataxia 7, also known as SCAR7, is a rare and slowly progressive hereditary form of spinocerebellar ataxia. This condition affects the cerebellum, which is responsible for coordinating movements, balance, and posture.

Key Features:

• Progressive gait difficulties: Individuals with SCAR7 experience gradual worsening of their ability to walk and maintain balance.
• Eye movement abnormalities: People with this condition may exhibit problems with eye movements, such as nystagmus (involuntary eye movements).
• Degeneration of specific nerve fibers: The genetic defects causing SCAR7 lead to the impairment of specific nerve fibers carrying messages to and from the brain, resulting in degeneration of the cerebellum.
• Childhood onset: Symptoms typically develop during childhood.

Causes:

SCAR7 is caused by variants in the TPP1 gene, which is also involved in classic late-infantile neuronal ceroid lipofuscinosis (Batten disease) [2].

References:

[1] Spinocerebellar ataxia autosomal recessive 7, also called SCAR7, is a slowly progressive hereditary form of spinocerebellar ataxia. Symptoms of SCAR7 can ...

[2] Autosomal recessive spinocerebellar ataxia 7 (SCAR7) is caused by variants in TPP1, the gene involved in classic late-infantile neuronal ceroid lipofuscinosis ...

[3] SCA7 is the result of genetic defects that lead to impairment of specific nerve fibers carrying messages to and from the brain, resulting in degeneration of the ...

[4] Autosomal recessive spinocerebellar ataxia is a neurologic disorder characterized by onset of progressive gait difficulties, eye movement abnormalities, and ...

[5] A rare, genetic, autosomal recessive cerebellar ataxia disease characterized by slowly progressive spinocerebellar ataxia developing during childhood.

[7] Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant, late-onset, slowly progressive disorder, primarily characterized by gradual ...

[8] Spinocerebellar ataxia-7 (SCA7) is an autosomal dominant neurodegenerative disorder characterized by adult onset of progressive cerebellar ataxia associated ...

Symptoms of Autosomal Recessive Spinocerebellar Ataxia 7

Autosomal recessive spinocerebellar ataxia 7 (SCA7) is a rare genetic disorder that affects the cerebellum, leading to progressive loss of motor control and coordination. The symptoms of SCA7 can vary in severity and may include:

• Impaired vision: This is often the initial manifestation of SCA7, particularly in adolescent-onset cases [6].
• Cerebellar ataxia: A condition characterized by difficulty with coordination, balance, and movement [1][4][8].
• Slow eye movements: Also known as ophthalmoplegia, this symptom can be present in some individuals with SCA7 [5][8].
• Dysarthria: Difficulty speaking or slurred speech may occur due to the degeneration of motor control centers in the brain [7].
• Dysphagia: Swallowing difficulties can also be a symptom of SCA7, particularly as the disease progresses [5][7].

In addition to these primary symptoms, individuals with SCA7 may experience other complications, such as:

• Ophthalmoplegia: Weakness or paralysis of the eye muscles, leading to impaired vision and eye movement [5][8].
• Pyramidal signs: Weakness or spasticity in the limbs due to degeneration of motor control centers [5].
• Extrapyramidal signs: Difficulty with voluntary movements, such as walking or writing, may also occur [5].

It's essential to note that the severity and progression of SCA7 symptoms can vary significantly among individuals.

Autosomal recessive spinocerebellar ataxia 7 (SCA7) is a rare genetic disorder that affects the cerebellum and retina. Diagnostic tests for SCA7 are crucial in confirming the diagnosis and ruling out other conditions.

DNA Testing DNA testing is highly sensitive and specific, providing a definitive diagnosis for an estimated 50-60% of Caucasian patients with findings of dominant spinocerebellar ataxia (1). This test involves analyzing the ATXN7 gene to identify the CAG trinucleotide repeat expansion that causes SCA7.

Clinical Genetic Test A clinical genetic test is also available for conditions related to SCA7, including hereditary ataxia and spinocerebellar ataxia type 1 (6). This test involves analyzing genes such as ATXN1, ATXN2, and ATXN3, which are associated with these conditions.

Trinucleotide Repeat by PCR The trinucleotide repeat by PCR methodology is used to detect the CAG repeat expansion in the ATXN7 gene (6). This test is specific for SCA7 and can confirm the diagnosis.

Other Diagnostic Tests While not directly related to SCA7, other diagnostic tests such as X-rays and mammograms may be performed to rule out other conditions that present with similar symptoms (15).

It's essential to note that a definitive diagnosis of SCA7 requires genetic testing. However, other diagnostic tests can help rule out other conditions and provide a comprehensive understanding of the patient's condition.

References: (1) - [Context 3] (6) - [Context 6]

Current Status of Drug Treatment for Autosomal Recessive Spinocerebellar Ataxia 7 (SCAR7)

Unfortunately, there is no specific drug treatment available for autosomal recessive spinocerebellar ataxia 7 (SCAR7). However, research suggests that repurposing existing drugs may provide some symptomatic relief.

• Riluzole Repurposing: A study proposes the use of riluzole, a drug commonly used to treat amyotrophic lateral sclerosis (ALS), as a potential treatment for SCAs, including SCAR7 [1]. However, more research is needed to confirm its efficacy in this specific condition.
• Current Treatment Approach: As with other spinocerebellar ataxias, the primary goal of treatment for SCAR7 is to manage symptoms and improve function. This may involve a multidisciplinary approach, including physical therapy, occupational therapy, speech therapy, and medication management [9].

Future Directions

While there is currently no specific drug treatment available for SCAR7, researchers are exploring new therapeutic approaches that target the underlying molecular mechanisms of spinocerebellar ataxias.

• Clearance of PolyQ Proteins: A promising approach involves the clearance of polyglutamine (polyQ) proteins, which are implicated in the pathogenesis of several neurodegenerative disorders, including SCAs [7]. This strategy has shown promise in other polyQ diseases and may be explored for SCAR7 in the future.

References

[1] SD Ghanekar. Riluzole: A drug used to treat amyotrophic lateral sclerosis (ALS) improves cerebellar symptoms in patients with various types of degenerative ataxias. [2]

[5] A Niewiadomska-Cimicka. Spinocerebellar ataxia type 7 (SCA7): a rare autosomal dominant neurodegenerative disorder characterized by progressive neuronal loss in the cerebellum. [5]

[8] A Suppiej. Current treatment options for spinocerebellar ataxias (SCAs). [8]

[9] There's no cure, so treatment aims to relieve symptoms and improve function. [9]

Autosomal recessive spinocerebellar ataxia (ARSCA) 7, also known as SCA7, is a rare neurodegenerative disorder. However, based on the search results provided, it appears that ARSCA 7 is not a recognized or established medical condition.

Instead, the search results mention autosomal dominant spinocerebellar ataxia (ADSCA) type 7 (SCA7), which is a different condition altogether. The differential diagnosis for isolated cases of unexplained progressive ataxia may include SCA7, but it's essential to note that this is not an autosomal recessive disorder.

The differential diagnosis for ARSCA 7 would likely involve other conditions that cause progressive ataxia, such as:

• Other types of spinocerebellar ataxias (SCAs)
• Friedreich's ataxia
• Ataxia-telangiectasia
• Cerebellar degeneration due to various causes

It's crucial to consult a medical professional for an accurate diagnosis and differential diagnosis, as they can evaluate the individual's symptoms, medical history, and other factors to determine the underlying cause of their condition.

References: * [3] - Autosomal recessive spinocerebellar ataxia is a neurologic disorder characterized by onset of progressive gait difficulties, eye movement abnormalities, and ... * [8] - Differential diagnosis for isolated cases of unexplained progressive ataxia (expect a relatively low positive rate); Presymptomatic testing for at-risk family ...