Autosomal Dominant Sensory Ataxia 1: Comprehensive Disease Report

Executive summary

Autosomal dominant sensory ataxia 1 (ADSA1; also SNAX1) is an exceptionally rare, adult-onset, slowly progressive neurodegenerative disorder caused by a heterozygous RNF170 c.595C>T (p.Arg199Cys) variant. Its defining abnormality is degeneration or dysfunction of proprioceptive sensory pathways—especially dorsal-root-ganglion neurons and/or their central projections in the posterior spinal columns—producing impaired vibration and joint-position sense, sensory gait ataxia, and a positive Romberg sign. Pyramidal signs, peripheral sensory-neuronopathy, and bilateral vestibular areflexia are variable extensions of the phenotype. The disorder is not primarily a cerebellar ataxia. Published dominant cases remain limited to a few Canadian, Ecuadorian, and Belgian/European families, precluding reliable estimates of prevalence, penetrance, survival, or phenotype frequencies. (cortese2020mutationinrnf170 pages 1-2, daele2022rnf170mutationcauses pages 2-4, wagner2019biallelicvariantsin pages 8-10, daele2022rnf170mutationcauses pages 1-2)

A crucial curation distinction is that biallelic loss-of-function RNF170 variants cause a separate, infancy-onset autosomal-recessive hereditary spastic paraplegia (HSP). Findings from that allelic disorder illuminate RNF170 biology but should not be assigned directly to ADSA1. (wagner2019biallelicvariantsin pages 8-10, wagner2019biallelicvariantsin pages 1-2, wagner2019biallelicvariantsin pages 3-4)

Table: This table summarizes the main curated findings for Autosomal Dominant Sensory Ataxia 1, emphasizing that the dominant disorder is specifically linked to heterozygous RNF170 p.Arg199Cys and is distinct from biallelic RNF170 hereditary spastic paraplegia. It also highlights the strongest available clinical and mechanistic evidence while clearly labeling major evidence gaps.

1. Disease information

Definition and classification

ADSA1 is a Mendelian, autosomal-dominant sensory ataxia characterized by late-onset progressive impairment of large-fiber proprioceptive pathways. The usual clinical syndrome comprises imbalance worsened by loss of visual input, sensory loss, gait ataxia, and posterior-column neurophysiological abnormalities. Sensory nerve action potentials (SNAPs) may remain preserved in the classic predominantly central/preganglionic phenotype, but some families exhibit sensory ganglionopathy with reduced or absent SNAPs. (wagner2019biallelicvariantsin pages 8-10, daele2022rnf170mutationcauses pages 4-5, cortese2020mutationinrnf170 pages 1-1)

Identifiers and synonyms

• MONDO: MONDO:0012166, autosomal dominant sensory ataxia 1.
• OMIM phenotype: MIM 608984, reported in the literature as autosomal dominant sensory ataxia/ADSA.
• Causal gene: RNF170, ring finger protein 170; Ensembl ENSG00000120925.
• Common names: autosomal dominant sensory ataxia; autosomal dominant sensory ataxia 1; ADSA; ADSA1; sensory ataxia 1; SNAX1; RNF170-related dominant sensory ataxia.
• Orphanet, MeSH, ICD-10, and ICD-11: no disease-specific codes were established from the retrieved evidence. In clinical coding, the condition will generally require broader hereditary ataxia or hereditary neuropathy categories; these are not exact semantic equivalents.

Open Targets maps MONDO:0012166 specifically to RNF170 and reports five association-evidence records, including literature linked to PMID 21115467. (OpenTargets Search: Autosomal dominant sensory ataxia 1)

Evidence provenance

The phenotype is derived primarily from individually examined members of a very small number of pedigrees, not from EHR-scale cohorts, population registries, or surveillance systems. MONDO/Open Targets and similar resources aggregate these family-level reports. Consequently, apparently precise clinical frequencies should not be generalized to the wider population.

2. Etiology, risk, and protective factors

Causal factor

The established cause is a germline heterozygous RNF170 c.595C>T (p.Arg199Cys) missense variant in a transmembrane region of RNF170. The same amino-acid substitution has been reported across geographically separated dominant families and remains the only heterozygous RNF170 variant convincingly linked to this specific phenotype in the retrieved literature. (cortese2020mutationinrnf170 pages 1-2, daele2022rnf170mutationcauses pages 2-4, daele2022rnf170mutationcauses pages 4-5)

Genetic risk

An affected heterozygote has, in principle, a 50% probability of transmitting the variant in each pregnancy. Family history is therefore the principal recognized risk factor. Two Eastern Canadian families shared a disease haplotype, supporting a founder event. Common ancestry with the Ecuadorian and Belgian families has not been demonstrated. Reduced penetrance or a de novo event was considered in the Belgian pedigree because the paternal grandparents reportedly remained asymptomatic beyond age 70. (daele2022rnf170mutationcauses pages 2-4)

Reliable age-specific penetrance, carrier frequency, population allele frequency, sex effect, germline-mosaicism rate, modifier genes, and genetic anticipation have not been established. There is no evidence of a repeat-expansion mechanism, so anticipation is not expected mechanistically, but this has not been tested in a sufficiently large cohort.

Environmental, lifestyle, infectious, and protective factors

No environmental toxin, lifestyle exposure, infection, diet, protective allele, or protective behavior has been shown to alter ADSA1 occurrence or progression. No disease-specific gene–environment interaction has been reported. Acquired toxic, autoimmune, nutritional, and paraneoplastic sensory neuronopathies are important differential diagnoses, not established modifiers of RNF170 disease. (cortese2020mutationinrnf170 pages 1-2, daele2022rnf170mutationcauses pages 2-4, cortese2020mutationinrnf170 pages 1-1)

3. Phenotypes

Core and variable manifestations

The Belgian family had onset at ages 35, 55, 64, and 68 years in four affected relatives. The Ecuadorian proband developed poor balance at 47 years and required a walking aid by 57; her father and grandmother reportedly began near age 60. Across earlier reports, onset ranged from the fourth through eighth decades. (cortese2020mutationinrnf170 pages 1-2, wagner2019biallelicvariantsin pages 8-10, daele2022rnf170mutationcauses pages 1-2)

Laboratory, neurophysiological, and imaging phenotypes

• Somatosensory evoked potentials: delayed, abnormal, or absent lower-extremity responses support posterior-column/preganglionic dysfunction.
• Nerve conduction: motor studies are generally normal. SNAPs may be preserved in classic Canadian disease but reduced or absent in Belgian and Ecuadorian cases, demonstrating genuine phenotypic variability rather than a mandatory normal sensory NCS.
• MRI: brain MRI can be normal without cerebellar atrophy. Cervical spinal MRI may show posterior-column T2 hyperintensity and volume loss, although normal spinal MRI has also been reported. Frontal atrophy was described in one Belgian evaluation but is not established as a defining feature.
• Vestibular testing: video head-impulse or equivalent testing may demonstrate reduced vestibulo-ocular-reflex gain bilaterally. (cortese2020mutationinrnf170 pages 1-1, daele2022rnf170mutationcauses pages 1-2, cortese2020mutationinrnf170 pages 2-2)

Quality-of-life effect

Progressive imbalance, loss of position sense, and vestibular impairment increase falls, restrict independent mobility, and may eventually require a cane, walker, or other aid. No ADSA1-specific EQ-5D, SF-36, PROMIS, employment, caregiver-burden, or activities-of-daily-living datasets were found. The Ecuadorian case provides direct evidence of meaningful mobility disability over approximately ten years. (cortese2020mutationinrnf170 pages 1-2)

4. Genetic and molecular information

Gene and variant

• Gene: RNF170, encoding an endoplasmic-reticulum membrane RING-finger E3 ubiquitin ligase.
• Dominant ADSA1 variant: NM transcript-dependent notation c.595C>T; p.Arg199Cys (R199C).
• Variant class: germline heterozygous missense substitution in a transmembrane region.
• Population frequency: no numerical gnomAD, TOPMed, 1000 Genomes, or ExAC frequency was recovered; the familial evidence and scarcity of reports imply extreme rarity, but a database value should be checked directly before production curation.
• Clinical classification: the family-level segregation and repeated phenotype association support pathogenicity for ADSA1. A current ClinVar assertion and review status were not independently recovered and should not be inferred from the papers alone.
• Somatic status: no somatic disease mechanism is known.

Arg199's positive charge appears important for ionic interactions that stabilize the transmembrane region. The substitution is associated with reduced RNF170 abundance through increased autoubiquitination and proteasomal degradation, but the dominant clinical mechanism is not adequately explained by simple haploinsufficiency because heterozygous carriers of truncating variants can be unaffected. A variant-specific toxic gain of function is therefore favored, although the exact toxic species and basis of sensory-neuron selectivity remain unresolved. (daele2022rnf170mutationcauses pages 2-4, wagner2019biallelicvariantsin pages 8-10, cook2024rnf170frameshiftdeletion pages 10-12, wagner2019biallelicvariantsin pages 10-11)

Allelic-disorder warning

Biallelic RNF170 variants—including splice, missense, multiexon/genomic-deletion, and frameshift alleles—cause an autosomal-recessive HSP with onset usually before age five, progressive lower-limb spasticity, and frequent optic atrophy. Wagner et al. studied nine affected individuals from four families; seven had optic atrophy and median onset was two years. These variants and phenotypes must not be entered as ADSA1-associated dominant variants. (wagner2019biallelicvariantsin pages 8-10, wagner2019biallelicvariantsin pages 3-4)

No established ADSA1 modifier gene, chromosomal abnormality, DNA-methylation signature, histone alteration, or chromatin mechanism was identified.

5. Environmental information

ADSA1 is a monogenic inherited disorder. No evidence supports pollution, radiation, occupation, smoking, alcohol, diet, physical inactivity, or infectious agents as causal or triggering factors. Avoiding neurotoxic exposures—such as excessive pyridoxine or certain chemotherapy agents—is prudent in a person with sensory dysfunction but represents prevention of superimposed neuropathy, not prevention of RNF170 disease. (cortese2020mutationinrnf170 pages 1-2, cortese2020mutationinrnf170 pages 1-1)

6. Mechanism and pathophysiology

Normal pathway

RNF170 is an ER-membrane E3 ubiquitin ligase. Following activation of inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs), the ERLIN1–ERLIN2 complex recruits RNF170, which ubiquitinates the activated receptors and directs them toward ER-associated degradation and proteasomal turnover. This feedback limits IP3-mediated calcium release from the ER and helps restore calcium homeostasis. (wagner2019biallelicvariantsin pages 10-11, wagner2019biallelicvariantsin pages 1-2, wagner2019biallelicvariantsin pages 11-12)

The abstract of Wagner et al. states directly: “We provide evidence that mutations in the ubiquitin E3 ligase gene RNF170, which targets inositol 1,4,5-trisphosphate receptors for degradation, are the likely cause of autosomal recessive HSP in four unrelated families.” It further concludes that the findings “highlight inositol 1,4,5-trisphosphate signaling as a candidate key pathway for hereditary spastic paraplegias and cerebellar ataxias.” Although this experiment concerned recessive HSP, the biochemical pathway is relevant to interpreting dominant RNF170 disease. (wagner2019biallelicvariantsin pages 1-2)

Proposed ADSA1 causal chain

1. Upstream genetic trigger: heterozygous p.Arg199Cys alters a critical RNF170 transmembrane residue.
2. Protein effect: altered intramembrane interactions and RNF170 instability, with increased autoubiquitination/proteasomal turnover.
3. Pathway disturbance: dysregulated RNF170–ERLIN1/2–IP3R quality control and abnormal ER calcium signaling; available data favor a p.Arg199Cys-specific toxic gain of function rather than generic dosage loss.
4. Cellular vulnerability: long-projecting proprioceptive sensory neurons—dorsal-root-ganglion neurons and their posterior-column axons—are preferentially impaired or lost. The reason for this selectivity is unknown.
5. Tissue pathology: dysfunction/degeneration of central sensory tracts, with variable ganglionic/postganglionic and vestibular involvement.
6. Clinical output: loss of proprioceptive input causes Romberg-positive sensory ataxia; involvement of corticospinal pathways adds pyramidal signs, and vestibular involvement can produce a CANVAS-like syndrome. (cortese2020mutationinrnf170 pages 1-2, wagner2019biallelicvariantsin pages 8-10, daele2022rnf170mutationcauses pages 4-5, wagner2019biallelicvariantsin pages 10-11)

Suggested ontology annotations

• GO biological process: protein ubiquitination (GO:0016567); ER-associated ubiquitin-dependent protein catabolic process (GO:0030433); proteasome-mediated ubiquitin-dependent protein catabolic process (GO:0043161); regulation of cytosolic calcium-ion concentration (GO:0051480); inositol-1,4,5-trisphosphate-sensitive calcium-release channel activity pathway.
• GO molecular function: ubiquitin-protein transferase activity (GO:0004842); ligase activity (GO:0016874).
• GO cellular component: endoplasmic-reticulum membrane (GO:0005789); integral component of ER membrane.
• Cell Ontology: sensory neuron (CL:0000526); peripheral sensory neuron (CL:0000101); dorsal-root-ganglion neuron; proprioceptor (CL:0000199).

No disease-specific human transcriptomic, proteomic, metabolomic, lipidomic, single-cell, spatial-transcriptomic, CRISPR-screen, or multi-omics profile was found. Immune activation, fibrosis, ischemia, primary mitochondrial failure, and a defined metabolic signature are not established components of ADSA1.

7. Anatomical structures affected

The nervous system is the primary affected system. Principal sites are bilateral and length-dependent rather than unilateral:

• dorsal-root ganglia and large myelinated sensory neurons;
• peripheral sensory axons in cases with ganglionopathy;
• posterior/dorsal columns of the cervical and more caudal spinal cord;
• proprioceptive pathways and somatosensory projections;
• variably, corticospinal tracts and bilateral vestibular pathways.

The cerebellum may be structurally normal; therefore, “ataxia” should not automatically be annotated as primary cerebellar degeneration. No consistent involvement of heart, lung, kidney, endocrine, gastrointestinal, or immune organs has been established. (wagner2019biallelicvariantsin pages 8-10, cortese2020mutationinrnf170 pages 1-1, cortese2020mutationinrnf170 pages 2-2)

Suggested anatomy terms include UBERON:0000955 nervous system, UBERON:0002240 spinal cord, UBERON:0002392 dorsal root ganglion, UBERON:0002291 posterior funiculus, and UBERON:0002037 cerebellum only when documenting a normal/differential assessment rather than proven primary disease.

8. Temporal development

Onset is chronic and insidious, typically in adulthood or later life. Published individual onsets range from 35 to 68 years, while summarized historical observations extend into the eighth decade. Early disease commonly consists of fatigue, imbalance, or distal sensory symptoms; intermediate disease adds marked proprioceptive loss, Romberg positivity, and gait ataxia; advanced disease may include upper-limb sensory ataxia, sensory ganglionopathy, pyramidal signs, vestibular areflexia, and dependence on mobility aids. (cortese2020mutationinrnf170 pages 1-2, wagner2019biallelicvariantsin pages 8-10, daele2022rnf170mutationcauses pages 1-2)

The course is slowly progressive and lifelong. No relapsing-remitting pattern, spontaneous remission, disease stage system, validated progression rate, or critical therapeutic window has been defined.

9. Inheritance and population

Inheritance is autosomal dominant. Available reports support vertical transmission in both sexes, without evidence for sex limitation. The Canadian founder haplotype indicates a regional founder effect, but ADSA1 has also been detected in Ecuadorian and Belgian/European families. By 2022, the literature described two Canadian families, one Ecuadorian family, and one Belgian family; this is case ascertainment, not a population prevalence estimate. (daele2022rnf170mutationcauses pages 2-4, cortese2020mutationinrnf170 pages 1-2)

No defensible incidence per 100,000, prevalence per 100,000, carrier frequency, sex ratio, ethnic-risk estimate, or geographic burden is available. Penetrance is probably age-dependent but cannot be quantified. Expressivity is clearly variable: central posterior-column disease predominates in some families, whereas sensory ganglionopathy, pyramidal findings, or vestibular areflexia occur in others. Consanguinity is not relevant to the dominant disorder, though it is relevant to recessive RNF170-HSP.

10. Diagnostics

Clinical and physiological work-up

A practical diagnostic sequence is:

1. Document sensory rather than primary cerebellar ataxia: Romberg testing, vibration and joint-position sensation, reflexes, pinprick, pseudoathetosis, eye movements, and pyramidal signs.
2. Obtain motor and sensory NCS/EMG. Normal motor conduction with preserved or reduced/absent SNAPs is compatible with the spectrum.
3. Perform tibial/median SSEPs to identify central or preganglionic sensory-pathway dysfunction.
4. Obtain brain and cervical-spine MRI, looking for posterior-column signal/atrophy and assessing cerebellar structure.
5. If oscillopsia or a CANVAS-like presentation is present, assess vestibulo-ocular reflexes using video head-impulse testing, calorics, or rotational testing.
6. Exclude acquired sensory neuronopathy: nutritional deficiencies, paraproteinemia, Sjögren/autoimmune disease, paraneoplastic anti-Hu disease, infection where indicated, and medication/toxin exposure.
7. Conduct genetic testing. (cortese2020mutationinrnf170 pages 1-2, cortese2020mutationinrnf170 pages 2-2, cortese2020mutationinrnf170 pages 1-1)

Genetic testing

Targeted sequencing of RNF170, including direct testing for c.595C>T, is appropriate when the phenotype and dominant pedigree are compelling. More commonly, RNF170 should be included in a hereditary ataxia, sensory-neuropathy, or combined ataxia/HSP panel. The Belgian authors specifically recommended RNF170 inclusion in ataxia panels, while the Ecuadorian report recommended RNF170 testing in RFC1-negative CANVAS-like disease with dominant family history. (cortese2020mutationinrnf170 pages 1-2, daele2022rnf170mutationcauses pages 1-2, daele2022rnf170mutationcauses pages 2-4)

Testing should usually first or concurrently address common repeat expansions because standard WES may miss them, especially biallelic RFC1 AAGGG expansions and dominant spinocerebellar-ataxia expansions. WES is useful when panel testing is negative; WGS may identify sequence and structural variants and improve repeat analysis if the validated pipeline supports it. CMA, karyotyping, FISH, mitochondrial testing, and RNA sequencing are not first-line ADSA1 tests unless other clinical or variant-specific evidence warrants them.

No formal society diagnostic criteria, biochemical biomarker, enzyme assay, liquid biopsy, epigenomic test, or validated prognostic biomarker exists.

Differential diagnosis

Key alternatives are RFC1-related CANVAS; Friedreich ataxia; dominant spinocerebellar ataxias; POLG-related mitochondrial sensory ataxia; vitamin-E deficiency; abetalipoproteinemia; CMT4C and other inherited neuropathies; Sjögren sensory neuronopathy; anti-Hu/paraneoplastic ganglionopathy; and pyridoxine-, cisplatin-, or other toxin-associated neuropathy. Absence of cerebellar atrophy, a dominant pedigree, prominent posterior-column physiology, and RNF170 p.Arg199Cys distinguish ADSA1, but no single clinical sign is pathognomonic. (daele2022rnf170mutationcauses pages 2-4, cortese2020mutationinrnf170 pages 1-1)

11. Outcome and prognosis

ADSA1 causes chronic progressive neurological disability, principally impaired balance, falls, and declining independent ambulation. One Ecuadorian patient progressed from initial imbalance at 47 to requiring a walking aid by 57. The late onset and absence of reported systemic organ failure suggest that morbidity rather than early mortality is the dominant concern, but available studies are too small to conclude that life expectancy is normal. (cortese2020mutationinrnf170 pages 1-2)

No five- or ten-year survival rate, standardized disability trajectory, mortality rate, recovery rate, or quality-of-life score is available. Neurological recovery is not documented; stabilization with supportive care has not been quantified. Potential adverse prognostic features—earlier onset, ganglionopathy, pyramidal involvement, or vestibular areflexia—are plausible but unvalidated.

12. Treatment and current implementation

No disease-modifying pharmacotherapy, approved RNF170-targeted therapy, gene therapy, ASO, siRNA, cell therapy, immunotherapy, surgical treatment, pharmacogenomic rule, or genotype-specific treatment algorithm exists. The ClinicalTrials.gov search retrieved no relevant disease-specific interventional trial. Published human reports do not provide response rates or controlled treatment outcomes. (cortese2020mutationinrnf170 pages 1-2, daele2022rnf170mutationcauses pages 1-2)

Current care is supportive and should be individualized:

• neurologic and rehabilitation follow-up;
• physical therapy for balance, strength, gait, and safe transfers;
• occupational therapy and home-safety modification;
• cane, trekking poles, walker, orthoses, or wheelchair as needed;
• vestibular rehabilitation when bilateral hypofunction is present;
• fall prevention, footwear and foot inspection where sensation is reduced;
• treatment of neuropathic pain or dysesthesia using standard agents when present;
• correction of superimposed nutritional deficiencies and avoidance of sensory neurotoxins;
• genetic counseling and family cascade testing.

Suggested NCIt intervention concepts include Physical Therapy (NCIT:C15308), Occupational Therapy, Rehabilitation Therapy, Genetic Counseling (NCIT:C15241), and Assistive Device. These are supportive interventions extrapolated from neurological rehabilitation practice, not ADSA1-tested treatments.

The RNF170–ERLIN–IP3R pathway is a biologically plausible therapeutic target, but indiscriminate inhibition or enhancement could disrupt calcium homeostasis. Expert interpretation should therefore treat pathway modulation as preclinical, not clinically actionable. (wagner2019biallelicvariantsin pages 10-11, wagner2019biallelicvariantsin pages 1-2)

13. Prevention

Primary prevention through lifestyle modification or immunization is not possible for a germline dominant disorder. Secondary prevention consists of early molecular diagnosis, cascade testing of adult relatives who choose testing, baseline neurological assessment, and early fall-risk intervention. Tertiary prevention includes rehabilitation, mobility aids, home modification, vestibular therapy, prevention of injury, and avoidance of additional neuropathic insults.

After identification of a familial pathogenic variant, prenatal diagnosis and preimplantation genetic testing are technically feasible. Predictive testing of asymptomatic adults requires counseling about uncertain age-specific penetrance and the absence of preventive disease-modifying therapy. Testing minors for a usually adult-onset disorder should follow established ethics guidance and generally be deferred unless a clear childhood medical benefit emerges.

14. Other species and natural disease

A 2024 study/preprint reported naturally occurring autosomal-recessive neuroaxonal dystrophy in Miniature American Shepherd dogs (Canis lupus familiaris; NCBI Taxon 9615) caused by RNF170 c.367delG, p.Ala123Glnfs*11. Affected young-adult dogs developed pelvic-limb weakness and ataxia; 23/27 homozygotes (85%) were clinically affected, and linkage reached LOD 9.70. The abstract states that the deletion “perfectly segregates in an autosomal recessive pattern” and describes the dogs as an opportunity for therapeutic trials because of their relatively long lifespan. (cook2024rnf170frameshiftdeletion pages 10-12)

This is a valuable large-animal model of RNF170-associated neurodegeneration, but it models recessive truncating loss of function and neuroaxonal dystrophy—not human dominant p.Arg199Cys ADSA1. No zoonotic transmission is applicable, and no naturally occurring nonhuman disease with the exact dominant human variant was identified.

15. Model organisms

Mouse

Rnf170-null mice develop age-dependent gait abnormalities at approximately 12 months, involving interlimb coupling and step-sequence organization. They support a role for RNF170 in long-term nervous-system integrity but are loss-of-function models and do not reproduce the human heterozygous p.Arg199Cys mechanism exactly. (cook2024rnf170frameshiftdeletion pages 10-12, wagner2019biallelicvariantsin pages 10-11)

Zebrafish

Zebrafish knockdown and RNF170-expression experiments demonstrate developmental and neuronal consequences of disturbed RNF170 function, including abnormal body axis, eye/brain development, and impaired neurogenesis in loss-of-function paradigms. Separate expression work found dose-dependent toxicity from Arg199Cys, supporting a variant-specific toxic effect. These assays are mechanistically informative but cannot model decades-long human sensory tract degeneration. (cortese2020mutationinrnf170 pages 1-2, wagner2019biallelicvariantsin pages 10-11, wagner2019biallelicvariantsin pages 8-10)

Cellular systems

Patient fibroblasts and engineered SH-SY5Y neuroblastoma cells have been used to measure RNF170 abundance and IP3R degradation. Recessive loss-of-function variants increase basal IP3R levels and impair ligand-stimulated receptor degradation, supporting the RNF170–ERLIN–IP3R–ERAD mechanism. These systems lack mature proprioceptive-neuron architecture and therefore do not explain selective posterior-column vulnerability. (wagner2019biallelicvariantsin pages 1-2, wagner2019biallelicvariantsin pages 11-12, wagner2019biallelicvariantsin pages 8-10)

No validated ADSA1 patient-derived iPSC proprioceptor, sensory organoid, conditional p.Arg199Cys knock-in mouse, or humanized large-animal model was identified. Developing such models is a major research priority.

Recent developments and evidence gaps

The most relevant recent development in 2023–2024 was the 2024 canine RNF170 frameshift model, which broadens comparative understanding and may provide a practical platform for longitudinal biomarker and treatment studies. It does not, however, resolve the dominant p.Arg199Cys mechanism. No 2023–2024 human ADSA1 natural-history cohort, therapeutic trial, molecular biomarker study, or multi-omics analysis was identified. The most recent directly informative human dominant-family study retrieved was published online in 2021/print 2022 and expanded the phenotype to variable pyramidal involvement. (daele2022rnf170mutationcauses pages 2-4, daele2022rnf170mutationcauses pages 1-2, cook2024rnf170frameshiftdeletion pages 10-12)

Highest-priority research needs are: international case aggregation; standardized NCS/SSEP/vestibular phenotyping; direct population-frequency and ClinVar curation; longitudinal disability and quality-of-life measurement; p.Arg199Cys knock-in and patient-iPSC sensory-neuron models; and experiments distinguishing altered IP3R regulation from other toxic RNF170 substrates.

Key publications

1. Foundational RNF170 association, literature indexed as PMID 21115467; linked by Open Targets to MONDO:0012166. (OpenTargets Search: Autosomal dominant sensory ataxia 1)
2. Cortese et al. “Mutation in RNF170 causes sensory ataxic neuropathy with vestibular areflexia: a CANVAS mimic.” Journal of Neurology, Neurosurgery & Psychiatry. Published September 2020. DOI/URL: https://doi.org/10.1136/jnnp-2020-323719. (cortese2020mutationinrnf170 pages 1-2)
3. Van Daele et al. “RNF170 mutation causes autosomal dominant sensory ataxia with variable pyramidal involvement.” European Journal of Neurology 29:345–349. Online September 2021/2022 volume. DOI/URL: https://doi.org/10.1111/ene.15091. (daele2022rnf170mutationcauses pages 2-4, daele2022rnf170mutationcauses pages 1-2)
4. Wagner et al. “Bi-allelic variants in RNF170 are associated with hereditary spastic paraplegia.” Nature Communications. Published October 2019. DOI/URL: https://doi.org/10.1038/s41467-019-12620-9. This is mechanistic/allelic-disorder evidence, not a dominant ADSA1 cohort. (wagner2019biallelicvariantsin pages 1-2, wagner2019biallelicvariantsin pages 3-4)
5. Kim et al. “Age-dependent gait abnormalities in mice lacking the Rnf170 gene linked to human autosomal-dominant sensory ataxia.” Human Molecular Genetics 24:7196–7206. Published December 2015. DOI/URL: https://doi.org/10.1093/hmg/ddv417. (cook2024rnf170frameshiftdeletion pages 10-12)
6. Cook et al. “RNF170 frameshift deletion in Miniature American Shepherd dogs with neuroaxonal dystrophy provides a naturally occurring model for human RNF170 phenotypic spectrum.” Posted February 2024. DOI/URL: https://doi.org/10.21203/rs.3.rs-3914204/v1. Its preprint/publication status should be checked before assigning the highest evidence grade. (cook2024rnf170frameshiftdeletion pages 10-12)

Overall evidence assessment: strong evidence links heterozygous RNF170 p.Arg199Cys to a recognizable autosomal-dominant sensory-ataxia syndrome, but virtually all clinical knowledge comes from a handful of families. Mechanistic evidence firmly places RNF170 in ER-associated IP3R ubiquitination and calcium regulation; the exact p.Arg199Cys dominant-toxic mechanism, neuronal selectivity, epidemiology, prognosis, and treatment remain incompletely defined.

References

1. (cortese2020mutationinrnf170 pages 1-2): Andrea Cortese, Ilaria Callegari, Riccardo Currò, Elisa Vegezzi, Silvia Colnaghi, Maurizio Versino, Enrico Alfonsi, Giuseppe Cosentino, Enzamaria Valente, Simone Gana, Cristina Tassorelli, Anna Pichiecchio, Alexander M Rossor, Enrico Bugiardini, Antonio Biroli, Daniela Di Capua, Henry Houlden, and Mary M Reilly. Mutation in rnf170 causes sensory ataxic neuropathy with vestibular areflexia: a canvas mimic. Journal of Neurology, Neurosurgery, and Psychiatry, 91:1237-1238, Sep 2020. URL: https://doi.org/10.1136/jnnp-2020-323719, doi:10.1136/jnnp-2020-323719. This article has 24 citations.

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3. (wagner2019biallelicvariantsin pages 8-10): Matias Wagner, Daniel P. S. Osborn, Ina Gehweiler, Maike Nagel, Ulrike Ulmer, Somayeh Bakhtiari, Rim Amouri, Reza Boostani, Faycal Hentati, Maryam M. Hockley, Benedikt Hölbling, Thomas Schwarzmayr, Ehsan Ghayoor Karimiani, Christoph Kernstock, Reza Maroofian, Wolfgang Müller-Felber, Ege Ozkan, Sergio Padilla-Lopez, Selina Reich, Jennifer Reichbauer, Hossein Darvish, Neda Shahmohammadibeni, Abbas Tafakhori, Katharina Vill, Stephan Zuchner, Michael C. Kruer, Juliane Winkelmann, Yalda Jamshidi, and Rebecca Schüle. Bi-allelic variants in rnf170 are associated with hereditary spastic paraplegia. Nature Communications, Oct 2019. URL: https://doi.org/10.1038/s41467-019-12620-9, doi:10.1038/s41467-019-12620-9. This article has 62 citations and is from a highest quality peer-reviewed journal.

4. (daele2022rnf170mutationcauses pages 1-2): Sien H. Van Daele, Matthieu Moisse, Valérie Race, Amélie Van Eesbeeck, Liesbeth Keldermans, Sascha Vermeer, Hilde Van Esch, Kristl G. Claeys, and Philip Van Damme. rnf170 mutation causes autosomal dominant sensory ataxia with variable pyramidal involvement. European Journal of Neurology, 29:345-349, Sep 2022. URL: https://doi.org/10.1111/ene.15091, doi:10.1111/ene.15091. This article has 9 citations and is from a domain leading peer-reviewed journal.

5. (wagner2019biallelicvariantsin pages 1-2): Matias Wagner, Daniel P. S. Osborn, Ina Gehweiler, Maike Nagel, Ulrike Ulmer, Somayeh Bakhtiari, Rim Amouri, Reza Boostani, Faycal Hentati, Maryam M. Hockley, Benedikt Hölbling, Thomas Schwarzmayr, Ehsan Ghayoor Karimiani, Christoph Kernstock, Reza Maroofian, Wolfgang Müller-Felber, Ege Ozkan, Sergio Padilla-Lopez, Selina Reich, Jennifer Reichbauer, Hossein Darvish, Neda Shahmohammadibeni, Abbas Tafakhori, Katharina Vill, Stephan Zuchner, Michael C. Kruer, Juliane Winkelmann, Yalda Jamshidi, and Rebecca Schüle. Bi-allelic variants in rnf170 are associated with hereditary spastic paraplegia. Nature Communications, Oct 2019. URL: https://doi.org/10.1038/s41467-019-12620-9, doi:10.1038/s41467-019-12620-9. This article has 62 citations and is from a highest quality peer-reviewed journal.

6. (wagner2019biallelicvariantsin pages 3-4): Matias Wagner, Daniel P. S. Osborn, Ina Gehweiler, Maike Nagel, Ulrike Ulmer, Somayeh Bakhtiari, Rim Amouri, Reza Boostani, Faycal Hentati, Maryam M. Hockley, Benedikt Hölbling, Thomas Schwarzmayr, Ehsan Ghayoor Karimiani, Christoph Kernstock, Reza Maroofian, Wolfgang Müller-Felber, Ege Ozkan, Sergio Padilla-Lopez, Selina Reich, Jennifer Reichbauer, Hossein Darvish, Neda Shahmohammadibeni, Abbas Tafakhori, Katharina Vill, Stephan Zuchner, Michael C. Kruer, Juliane Winkelmann, Yalda Jamshidi, and Rebecca Schüle. Bi-allelic variants in rnf170 are associated with hereditary spastic paraplegia. Nature Communications, Oct 2019. URL: https://doi.org/10.1038/s41467-019-12620-9, doi:10.1038/s41467-019-12620-9. This article has 62 citations and is from a highest quality peer-reviewed journal.

7. (OpenTargets Search: Autosomal dominant sensory ataxia 1): Open Targets Query (Autosomal dominant sensory ataxia 1, 1 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.

8. (cortese2020mutationinrnf170 pages 1-1): Andrea Cortese, Ilaria Callegari, Riccardo Currò, Elisa Vegezzi, Silvia Colnaghi, Maurizio Versino, Enrico Alfonsi, Giuseppe Cosentino, Enzamaria Valente, Simone Gana, Cristina Tassorelli, Anna Pichiecchio, Alexander M Rossor, Enrico Bugiardini, Antonio Biroli, Daniela Di Capua, Henry Houlden, and Mary M Reilly. Mutation in rnf170 causes sensory ataxic neuropathy with vestibular areflexia: a canvas mimic. Journal of Neurology, Neurosurgery, and Psychiatry, 91:1237-1238, Sep 2020. URL: https://doi.org/10.1136/jnnp-2020-323719, doi:10.1136/jnnp-2020-323719. This article has 24 citations.

9. (cortese2020mutationinrnf170 pages 2-2): Andrea Cortese, Ilaria Callegari, Riccardo Currò, Elisa Vegezzi, Silvia Colnaghi, Maurizio Versino, Enrico Alfonsi, Giuseppe Cosentino, Enzamaria Valente, Simone Gana, Cristina Tassorelli, Anna Pichiecchio, Alexander M Rossor, Enrico Bugiardini, Antonio Biroli, Daniela Di Capua, Henry Houlden, and Mary M Reilly. Mutation in rnf170 causes sensory ataxic neuropathy with vestibular areflexia: a canvas mimic. Journal of Neurology, Neurosurgery, and Psychiatry, 91:1237-1238, Sep 2020. URL: https://doi.org/10.1136/jnnp-2020-323719, doi:10.1136/jnnp-2020-323719. This article has 24 citations.

10. (wagner2019biallelicvariantsin pages 10-11): Matias Wagner, Daniel P. S. Osborn, Ina Gehweiler, Maike Nagel, Ulrike Ulmer, Somayeh Bakhtiari, Rim Amouri, Reza Boostani, Faycal Hentati, Maryam M. Hockley, Benedikt Hölbling, Thomas Schwarzmayr, Ehsan Ghayoor Karimiani, Christoph Kernstock, Reza Maroofian, Wolfgang Müller-Felber, Ege Ozkan, Sergio Padilla-Lopez, Selina Reich, Jennifer Reichbauer, Hossein Darvish, Neda Shahmohammadibeni, Abbas Tafakhori, Katharina Vill, Stephan Zuchner, Michael C. Kruer, Juliane Winkelmann, Yalda Jamshidi, and Rebecca Schüle. Bi-allelic variants in rnf170 are associated with hereditary spastic paraplegia. Nature Communications, Oct 2019. URL: https://doi.org/10.1038/s41467-019-12620-9, doi:10.1038/s41467-019-12620-9. This article has 62 citations and is from a highest quality peer-reviewed journal.

11. (wagner2019biallelicvariantsin pages 11-12): Matias Wagner, Daniel P. S. Osborn, Ina Gehweiler, Maike Nagel, Ulrike Ulmer, Somayeh Bakhtiari, Rim Amouri, Reza Boostani, Faycal Hentati, Maryam M. Hockley, Benedikt Hölbling, Thomas Schwarzmayr, Ehsan Ghayoor Karimiani, Christoph Kernstock, Reza Maroofian, Wolfgang Müller-Felber, Ege Ozkan, Sergio Padilla-Lopez, Selina Reich, Jennifer Reichbauer, Hossein Darvish, Neda Shahmohammadibeni, Abbas Tafakhori, Katharina Vill, Stephan Zuchner, Michael C. Kruer, Juliane Winkelmann, Yalda Jamshidi, and Rebecca Schüle. Bi-allelic variants in rnf170 are associated with hereditary spastic paraplegia. Nature Communications, Oct 2019. URL: https://doi.org/10.1038/s41467-019-12620-9, doi:10.1038/s41467-019-12620-9. This article has 62 citations and is from a highest quality peer-reviewed journal.

12. (cook2024rnf170frameshiftdeletion pages 10-12): Shawna R. Cook, Cleo Schwarz, Julien Guevar, Charles-Antoine Assenmacher, Maeve Sheehy, Nathan Fanzone, Molly E. Church, Leonardo Murgiano, Margret L. Casal, Vidhya Jagannathan, Rodrigo Gutierrez-Quintana, Mark Lowrie, Frank Steffen, Tosso Leeb, and Kari J. Ekenstedt. Rnf170 frameshift deletion in miniature american shepherd dogs with neuroaxonal dystrophy provides a naturally occurring model for human rnf170 phenotypic spectrum. Unknown journal, Feb 2024. URL: https://doi.org/10.21203/rs.3.rs-3914204/v1, doi:10.21203/rs.3.rs-3914204/v1.

13. (daele2022rnf170mutationcauses pages 4-5): Sien H. Van Daele, Matthieu Moisse, Valérie Race, Amélie Van Eesbeeck, Liesbeth Keldermans, Sascha Vermeer, Hilde Van Esch, Kristl G. Claeys, and Philip Van Damme. rnf170 mutation causes autosomal dominant sensory ataxia with variable pyramidal involvement. European Journal of Neurology, 29:345-349, Sep 2022. URL: https://doi.org/10.1111/ene.15091, doi:10.1111/ene.15091. This article has 9 citations and is from a domain leading peer-reviewed journal.

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