spinocerebellar ataxia with axonal neuropathy 1

Spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1) is a rare, genetic neurological disorder characterized by a late childhood onset of slowly progressive cerebellar ataxia [4][6]. The condition is caused by a specific point mutation in the tyrosyl-DNA phosphodiesterase (TDP1) gene [5].

The clinical spectrum of SCAN1 includes mild cognitive deficits [8], and common symptoms include:

• Progressive ataxia, which affects coordination and balance
• Cerebellar atrophy, which can be detected through brain imaging
• Distal sensorimotor axonal neuropathy, which affects the nerves in the hands and feet
• Gaze nystagmus and dysarthria, which are symptoms of cerebellar dysfunction
• Areflexia, which is a loss of reflexes in the limbs
• Loss of pain, vibration, and touch sensations in the upper and lower extremities [11]

As the disease advances, patients may experience impaired pain and touch sensation in the hands and feet, as well as lost vibration sense in the hands and lower thighs [12].

SCAN1 is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [13]. It is essential to note that SCAN1 is an exceedingly rare disorder, having been documented in only a single family from Saudi Arabia [15].

Overall, spinocerebellar ataxia with axonal neuropathy type 1 is a complex and rare neurological disorder that affects coordination, balance, and sensation.

Spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1) is a rare genetic neurological disorder characterized by a late childhood onset of slowly progressive cerebellar ataxia. The initial manifestations include weakness and atrophy of distal limb muscles, areflexia, and loss of pain, vibration, and touch sensations in upper and lower extremities [10].

As the disease advances, individuals may experience gaze nystagmus and dysarthria, which develop after the onset of ataxic gait. Pain and touch sensation in the hands and feet become impaired, with vibration sense lost in hands and lower limbs [2]. Other signs and symptoms may include sensorimotor neuropathy, mild cognitive impairment, and less commonly, movement disorders.

Approximately half of affected people also experience oculomotor apraxia, which makes it difficult to move the eyes from side-to-side in the desired direction. It's essential to note that the progression and severity of SCAN1 can vary significantly among individuals [11].

In addition to these symptoms, some people with SCAN1 may experience other complications such as:

• Tingling or pain in the arms and legs (sensory neuropathy)
• Uncontrolled muscle tensing (dystonia)
• Muscle wasting (atrophy)
• Muscle twitches (fasciculations)

It's worth noting that the symptoms of SCAN1 can be similar to those of other spinocerebellar ataxia types, making accurate diagnosis crucial for proper management and care [12].

Spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1) is a rare, genetic neurological disorder characterized by a late childhood onset of slowly progressive problems with movement. Diagnostic tests for SCAN1 are crucial in confirming the diagnosis and ruling out other conditions.

Diagnostic Criteria

While there is no consensus clinical diagnostic criteria for SCAN1, several studies have proposed diagnostic guidelines. According to [2], SCAN1 is suspected in individuals with the following clinical findings:

• Electrophysiologic studies showing axonal neuropathy
• Laboratory findings indicating a genetic mutation
• Brain imaging showing cerebellar atrophy

Diagnostic Tests

The following diagnostic tests may be used to diagnose SCAN1:

• Genetic testing: TDP1 mutation testing is recommended for individuals with recessive cerebellar ataxia with axonal neuropathy [5].
• Electrophysiologic studies: These studies can show axonal neuropathy, which is a characteristic feature of SCAN1.
• Brain imaging: MRI scans may show cerebellar atrophy, which is a hallmark of SCAN1.

Other Diagnostic Clues

While not diagnostic on their own, the following findings can provide helpful diagnostic clues:

• Family history: A family history of spinocerebellar ataxia or axonal neuropathy may suggest SCAN1.
• Clinical presentation: The late childhood onset and slowly progressive nature of symptoms are characteristic of SCAN1.

References

[2] Oct 22, 2007 — SCAN1 is suspected in individuals with the following clinical findings, electrophysiologic studies, laboratory findings, brain imaging, and ... [5] by P Scott · 2019 · Cited by 23 — TDP1 mutation testing should be included in the diagnostic panel of recessive cerebellar ataxia with axonal neuropathy. [8] Spinocerebellar ataxia with axonal neuropathy type 1 is a rare, genetic neurological disorder characterized by a late childhood onset of slowly progressive.

Spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1) is a rare genetic neurological disorder, and there is limited information available on its treatment. However, based on the search results, here are some insights into the current understanding of drug treatment for SCAN1:

• Riluzole: While riluzole is primarily used to treat amyotrophic lateral sclerosis (ALS), it has been found to improve cerebellar symptoms in patients with various types of degenerative ataxia, including spinocerebellar ataxias [1]. However, its effectiveness in treating SCAN1 specifically is unclear.
• No FDA-approved drugs: Currently, there are no FDA-approved drugs for the treatment of neurological disorders like spinocerebellar ataxia type 3 (SCA3), which shares some similarities with SCAN1 [4].
• Supportive care: The primary approach to managing SCAN1 symptoms involves supportive care provided by specialists in neurology, rehabilitation medicine, occupational therapy, and physical therapy [3]. This may include measures such as speech and language therapy, physical therapy, and occupational therapy to help manage the condition's progression.
• Experimental treatments: Some studies have explored the use of Topo I inhibitors or bleomycin to treat SCAN1, but these are still in the experimental stages and require further research [10].

In summary, while there is some evidence suggesting that riluzole may be beneficial for certain types of degenerative ataxia, its effectiveness in treating SCAN1 specifically is unclear. Supportive care remains the primary approach to managing SCAN1 symptoms, with ongoing research exploring potential experimental treatments.

References:

[1] SD Ghanekar (2022) - Cited by 28 [3] MAM Salih (2022) - Cited by 1 [4] M Naveed (2024) - Cited by 9 [10] R Hirano (2007) - Cited by 174

Spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1) is a rare genetic neurological disorder characterized by a late childhood onset of slowly progressive cerebellar ataxia. The differential diagnosis for SCAN1 includes several other conditions that present with similar symptoms.

Key Differential Diagnoses:

• Friedreich ataxia (FA): An autosomal recessive genetic disease caused by guanine-adenine-adenine (GAA) triplet repeat expansion in the frataxin (FXN) gene, leading to progressive damage to the nervous system [9].
• Ataxia with vitamin E deficiency: A rare condition characterized by progressive cerebellar ataxia and peripheral neuropathy due to a deficiency of vitamin E [4].
• Ataxia-oculomotor apraxia type 1 (AOA1): A rare genetic disorder that affects the nervous system, leading to progressive ataxia, oculomotor apraxia, and other neurological symptoms [3].
• Ataxia-telangiectasia: A rare genetic disorder characterized by progressive cerebellar ataxia, telangiectasias (dilated blood vessels), and immunodeficiency [4].

Other Conditions to Consider:

• Spinocerebellar ataxia type 1 (SCA1): A rare genetic disorder that affects the nervous system, leading to progressive cerebellar ataxia, dysarthria, and eventual deterioration of bulbar functions [2].
• Early-onset cerebellar ataxias with sensory axonal neuropathy: A group of conditions characterized by progressive cerebellar ataxia and peripheral neuropathy [7].

Diagnostic Approach:

A methodical approach to the diagnostic workup is suggested, including a thorough clinical evaluation, electrophysiologic testing, brain imaging, and molecular genetic testing. The diagnosis of SCAN1 is established in a proband with characteristic clinical findings and an abnormal CAG repeat expansion in ATXN1 identified by molecular genetic testing [13].

References:

• Mustafa AM Salih et al. (2022). Spinocerebellar ataxia with axonal neuropathy type 1. In: Molecular Genetics Chapter Notes.
• Cornelius et al. (2019). The association to a peripheral sensory axonal neuropathy was described later on, with neuropathological studies demonstrating that both sensory neuropathy and vestibular areflexia were diffuse ganglionopathy.
• Hiroshi Takashima et al. (2020). Neuropathy is a common associated feature of different types of genetic or sporadic cerebellar ataxias.

Note: The above information is based on the search results provided within the context.