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Familial Isolated Vitamin E Deficiency

Familial Isolated Vitamin E Deficiency (AVED) — Comprehensive Disease Characteristics Report

2026-06-03
Falcon MONDO:0010188 Model: Edison Scientific Literature 21 citations

Familial Isolated Vitamin E Deficiency (AVED) — Comprehensive Disease Characteristics Report

1. Disease Information

Overview / definition

Familial isolated vitamin E deficiency—also referred to as ataxia with isolated vitamin E deficiency (AVED)—is a rare, potentially treatable autosomal recessive neurodegenerative disorder caused by impaired hepatic handling/transport of α‑tocopherol (vitamin E), leading to very low circulating vitamin E and progressive neurologic disease resembling Friedreich ataxia (FA). (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23)

Key identifiers and nomenclature

Synonyms / alternative names

Evidence sources (individual vs aggregated)

The information summarized here is derived primarily from aggregated cohorts (e.g., multicenter family series) and individual case reports describing biochemically and genetically confirmed AVED. (cavalier1998ataxiawithisolated pages 7-8, holla2024geneticallyprovenataxia pages 1-2, iwasa2014retinitispigmentosaand pages 2-3, hoshino1999ataxiawithisolated pages 22-23)

2. Etiology

Disease causal factors

Primary cause: biallelic pathogenic variants in TTPA, encoding α‑tocopherol transfer protein (α‑TTP/αTTP). (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23)

Mechanistically, α‑TTP binds α‑tocopherol and supports its incorporation into circulating lipoproteins (e.g., VLDL); dysfunction yields very low serum/plasma vitamin E despite preserved intestinal absorption. (holla2024geneticallyprovenataxia pages 1-2, iwasa2014retinitispigmentosaand pages 2-3)

Risk factors

Protective factors

Gene–environment interactions

Direct gene–environment interactions were not described in the available evidence. The most actionable interaction is genotype × timing of treatment, where delayed supplementation is associated with incomplete reversibility of neurologic deficits. (esmer2013clinicalandmolecular pages 2-4)

3. Phenotypes

Core clinical phenotype

AVED typically presents with a FA-like neurologic syndrome including: * Progressive gait/limb ataxia (stoiloudis2022vitaminedeficiency pages 42-44, hoshino1999ataxiawithisolated pages 22-23) * Hyporeflexia/areflexia (stoiloudis2022vitaminedeficiency pages 42-44, hoshino1999ataxiawithisolated pages 22-23) * Loss of proprioception and vibration sense (posterior column involvement) (stoiloudis2022vitaminedeficiency pages 42-44, hoshino1999ataxiawithisolated pages 22-23) * Dysarthria (stoiloudis2022vitaminedeficiency pages 42-44) * Peripheral neuropathy/sensory involvement (iwasa2014retinitispigmentosaand pages 2-3)

Additional/variable features: * Head titubation / tremor; dystonia (cavalier1998ataxiawithisolated pages 7-8, stoiloudis2022vitaminedeficiency pages 42-44) * Extensor plantar response / Babinski (stoiloudis2022vitaminedeficiency pages 42-44) * Retinopathy/retinitis pigmentosa; macular degeneration in some individuals, particularly with long-standing deficiency (iwasa2014retinitispigmentosaand pages 2-3, hoshino1999ataxiawithisolated pages 22-23) * Cardiomyopathy occurs but at lower frequency than FA in cohort data (cavalier1998ataxiawithisolated pages 7-8, stoiloudis2022vitaminedeficiency pages 42-44)

Phenotype statistics from a recent compiled frequency table

A review snippet reports phenotype frequencies (interpretable as proportion of affected individuals in the compiled dataset): * Absent tendon reflexes 94.7% * Gait disturbance 93.4% * Plantar extensor response 85.5% * Posterior column involvement 67.1% * Speech disturbance/dysarthria 61.8% * Head titubation 40.8% * Retinitis pigmentosa 2.3% * Cardiomyopathy 1.5% (stoiloudis2022vitaminedeficiency pages 42-44)

A large family series found cardiomyopathy 19%, head titubation 28%, and dystonia 13% (in addition to the FA-like presentation). (cavalier1998ataxiawithisolated pages 7-8)

Age of onset and progression

Suggested HPO terms (examples)

(These HPO codes are suggested to standardize phenotype capture; detailed mapping should be verified against the current HPO release.)

4. Genetic / Molecular Information

Causal gene

Protein and molecular role

α‑TTP binds α‑tocopherol and enables its export from the liver into circulating lipoproteins (described as incorporation into VLDL), supporting systemic delivery of vitamin E; deficiency leads to neuronal oxidative injury. (holla2024geneticallyprovenataxia pages 1-2, iwasa2014retinitispigmentosaand pages 2-3)

Inheritance

Autosomal recessive; many reported individuals are homozygous in consanguineous families or biallelic (including compound heterozygous) in non-consanguineous settings. (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23)

Pathogenic variants (examples explicitly described in retrieved evidence)

Genotype–phenotype correlation

One large series distinguished milder vs more severe functional classes and reported that some missense variants (e.g., H101Q) can be associated with milder, later-onset phenotypes, whereas truncating/nonconservative variants associate with earlier/severe disease. (cavalier1998ataxiawithisolated pages 7-8)

Population allele frequencies / gnomAD

Population allele frequencies were not available in the retrieved evidence and are not reported here.

5. Environmental Information

AVED is fundamentally genetic; non-genetic contributors are mainly secondary causes of vitamin E deficiency that are important for differential diagnosis (e.g., fat malabsorption syndromes) rather than etiologic contributors to familial isolated deficiency. Cohort/case evidence emphasizes that AVED patients can have intact intestinal absorption with low circulating vitamin E. (holla2024geneticallyprovenataxia pages 1-2, cavalier1998ataxiawithisolated pages 7-8)

6. Mechanism / Pathophysiology

Causal chain (current understanding from retrieved evidence)

  1. Biallelic TTPA pathogenic variants → defective α‑TTP function (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23)
  2. Impaired hepatic handling/export of α‑tocopherol via circulating lipoproteins (VLDL described) → very low serum/plasma α‑tocopherol despite intact absorption (holla2024geneticallyprovenataxia pages 1-2, iwasa2014retinitispigmentosaand pages 2-3)
  3. Reduced antioxidant capacity in nervous system → oxidative injury to neurons (explicitly invoked as mechanism in a 2024 case report) (holla2024geneticallyprovenataxia pages 1-2)
  4. Progressive neurodegeneration of cerebellar and sensory pathways → ataxia, proprioceptive loss, neuropathy, pyramidal signs, and in some patients retinal degeneration and cardiomyopathy. (stoiloudis2022vitaminedeficiency pages 42-44, iwasa2014retinitispigmentosaand pages 2-3)

Molecular pathways / processes (ontology suggestions)

  • GO Biological Process (suggested):
  • response to oxidative stress — GO:0006979
  • lipid transport — GO:0006869
  • regulation of lipid localization — GO:1905952
  • GO Cellular Component (suggested):
  • very-low-density lipoprotein particle — GO:0034361
  • Cell types (CL suggestions):
  • hepatocyte — CL:0000182 (site of major α‑TTP expression/function implied by hepatic export role)
  • neuron — CL:0000540 (target of oxidative injury)

(These terms are proposed for KB standardization; the retrieved evidence provides qualitative support for oxidative injury and lipoprotein-mediated trafficking but does not provide a full pathway map.)

Molecular profiling (transcriptomics/proteomics/metabolomics)

Not reported in the retrieved evidence.

7. Anatomical Structures Affected

Primary systems/organs

Suggested UBERON terms (examples)

8. Temporal Development

Onset

Typically late childhood/early adolescence, but can range to adult onset depending on genotype and other factors. (holla2024geneticallyprovenataxia pages 1-2, zhang2021clinicalandgenetic pages 1-4)

Course

Progressive without treatment; vitamin E therapy can halt progression and stabilize or partially improve signs, especially when initiated early. (esmer2013clinicalandmolecular pages 2-4, cavalier1998ataxiawithisolated pages 7-8, mariotti2004ataxiawithisolated pages 7-10)

9. Inheritance and Population

Inheritance pattern

Autosomal recessive. (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23)

Epidemiology / distribution

Robust prevalence/incidence estimates were not available in the retrieved evidence. However: * Recurrent mutation patterns suggest enrichment in North Africa / Mediterranean populations (e.g., c.744delA described as a major mutation in North Africa). (esmer2013clinicalandmolecular pages 2-4)

Founder effects

Founder/recurrent alleles are reported in specific regions: * c.744delA: emphasized as a major/frequent mutation in North Africa / Mediterranean (esmer2013clinicalandmolecular pages 2-4, zhang2021clinicalandgenetic pages 1-4) * Additional recurrent European-origin alleles noted: c.513_514insTT, c.486delT, c.400C>T (esmer2013clinicalandmolecular pages 2-4)

Carrier frequency and penetrance were not provided in the retrieved evidence.

10. Diagnostics

Core diagnostic pattern (real-world implementation)

AVED is suggested by: 1. Neurologic syndrome resembling FA (ataxia, areflexia, posterior column signs) (hoshino1999ataxiawithisolated pages 22-23) 2. Markedly low plasma/serum α‑tocopherol (vitamin E) with otherwise non-explanatory routine workup; multiple case reports emphasize low α‑tocopherol (e.g., 0.12 mg/dL reported in one case) (iwasa2014retinitispigmentosaand pages 2-3) 3. Evidence that intestinal absorption may be intact and lipid profile may be normal (noted explicitly in a 2024 case report and other descriptions) (holla2024geneticallyprovenataxia pages 1-2, vera2021pearls&oysters pages 1-5) 4. Confirmatory genetic testing demonstrating biallelic TTPA pathogenic variants (holla2024geneticallyprovenataxia pages 1-2)

One report states that diagnostic testing should include α‑tocopherol determination and that AVED levels should be <1.7 mg/L. (esmer2013clinicalandmolecular pages 2-4)

Genetic testing modalities

Evidence supports use of: * Single-gene sequencing of TTPA (with exon/intron junction evaluation in one report; mutation detection rate stated as ~90% in that source) (esmer2013clinicalandmolecular pages 2-4) * Whole exome sequencing (WES) as a practical route to diagnosis after excluding common ataxias (zhang2021clinicalandgenetic pages 1-4)

Differential diagnosis (examples from evidence context)

11. Outcome / Prognosis

Natural history

Without therapy, AVED is progressive and can lead to substantial disability. (esmer2013clinicalandmolecular pages 2-4)

Treatment-modified prognosis

Multiple sources stress that early initiation of vitamin E can halt progression and may improve established signs, whereas delayed therapy may leave residual irreversible deficits (e.g., persistent proprioceptive/gait impairment). (esmer2013clinicalandmolecular pages 2-4, cavalier1998ataxiawithisolated pages 7-8)

12. Treatment

Disease-specific therapy: vitamin E replacement

High-dose oral vitamin E (α‑tocopherol) is the central disease-modifying intervention.

Evidence-based statements on benefit: * “The administration of vitamin E supplements in divided doses daily has resulted in cessation of progression … and in amelioration of established neurological abnormalities.” (cavalier1998ataxiawithisolated pages 7-8) * Early supplementation is highlighted as necessary “before irreversible damage develops.” (cavalier1998ataxiawithisolated pages 7-8)

Dosing (examples explicitly reported)

Outcomes

Supportive/rehabilitative therapies

Symptomatic pharmacotherapy may be used for movement disorder components (e.g., dystonia treated with clonazepam and trihexyphenidyl in a 2024 case report). (holla2024geneticallyprovenataxia pages 1-2)

Suggested MAXO terms (examples)

13. Prevention

Primary/secondary/tertiary prevention

In AVED, “prevention” is primarily secondary/tertiary through: * Early biochemical screening for vitamin E deficiency in patients with FA-like ataxia and prompt genetic confirmation (cavalier1998ataxiawithisolated pages 7-8) * Lifelong vitamin E therapy to prevent progression/complications (esmer2013clinicalandmolecular pages 2-4)

Prenatal/preimplantation options were not discussed in the retrieved evidence.

14. Other Species / Natural Disease

Cross-species disease analogs for TTPA were not established in the retrieved evidence for AVED itself.

15. Model Organisms

The retrieved evidence set used for this report did not include detailed model organism phenotyping for AVED; therefore model organism details are not reported here.

Recent developments and latest research (prioritizing 2023–2024)

2024: Phenotypic expansion / diagnostic reminder

A 2024 case report emphasizes that AVED can present with prominent cervicobrachial dystonic tremor and may have normal MRI, reinforcing the need to consider AVED in atypical movement disorder presentations because it is “potentially treatable.” (Journal of Movement Disorders, Apr 2024; https://doi.org/10.14802/jmd.23227) (holla2024geneticallyprovenataxia pages 1-2)

Ongoing research gap

Within the retrieved evidence, there were no disease-specific interventional clinical trials captured for AVED, consistent with AVED management being dominated by replacement therapy rather than novel therapeutics (clinical trial retrieval returned no relevant AVED trials).

Practical applications / real-world implementation summary

Structured summary table

Table (click to expand)
Disease / synonym(s) Key identifiers explicitly supported in evidence Causal gene / protein Inheritance Hallmark laboratory finding Typical onset Core phenotypes (with frequency when available) Recurrent / founder or notable variants mentioned Treatment and outcomes Key references
Familial isolated vitamin E deficiency; Ataxia with isolated vitamin E deficiency (AVED); Ataxia with vitamin E deficiency (cavalier1998ataxiawithisolated pages 7-8, hoshino1999ataxiawithisolated pages 22-23) OMIM/MIM 277460 explicitly stated for AVED (hoshino1999ataxiawithisolated pages 22-23); TTPA transcript/protein entry noted as OMIM*600415 in one report (zhang2021clinicalandgenetic pages 1-4) TTPA encoding α-tocopherol transfer protein (α-TTP / αTTP); α-TTP binds α-tocopherol and mediates incorporation into VLDL / circulating lipoproteins (zhang2021clinicalandgenetic pages 1-4, iwasa2014retinitispigmentosaand pages 2-3) Autosomal recessive; biallelic / homozygous or compound heterozygous TTPA variants reported (holla2024geneticallyprovenataxia pages 1-2, hoshino1999ataxiawithisolated pages 22-23) Markedly low plasma/serum vitamin E (α-tocopherol) despite intact intestinal absorption and otherwise normal lipids in reported cases; one snippet notes AVED levels should be <1.7 mg/L (esmer2013clinicalandmolecular pages 2-4, vera2021pearls&oysters pages 1-5, holla2024geneticallyprovenataxia pages 1-2) Usually late childhood to early adolescence; broader reported range from early childhood/infancy to adulthood/fourth decade; untreated disease often manifests 5–15 years (holla2024geneticallyprovenataxia pages 1-2, zhang2021clinicalandgenetic pages 1-4, hoshino1999ataxiawithisolated pages 22-23) Friedreich-like phenotype with progressive ataxia, areflexia/hyporeflexia, loss of proprioception/vibration sense, dysarthria, sensory neuropathy; extra-neurologic/other features can include head titubation/dystonia, retinitis pigmentosa, scoliosis, cardiomyopathy. Frequency data from one review: absent tendon reflexes 94.7%, gait disturbance 93.4%, extensor plantar response 85.5%, posterior column involvement 67.1%, dysarthria 61.8%, head titubation 40.8%, retinitis pigmentosa 2.3%, cardiomyopathy 1.5% (stoiloudis2022vitaminedeficiency pages 42-44). Earlier cohort found cardiomyopathy 19%, head titubation 28%, dystonia 13% (cavalier1998ataxiawithisolated pages 7-8). Recurrent/founder variants mentioned: c.744delA major in North Africa / Mediterranean and associated with earlier/severe disease; c.513_514insTT, c.486delT, c.400C>T (R134X) in European-origin families; H101Q associated with milder, late-onset phenotype; additional reported variants include c.205-1G>C, c.473C>T (p.F185S), c.717delC (p.D239EfsX25), c.58dupC (p.His20ProfsTer56), and a start-codon mutation in a Japanese family (esmer2013clinicalandmolecular pages 2-4, cavalier1998ataxiawithisolated pages 7-8, holla2024geneticallyprovenataxia pages 1-2, zhang2021clinicalandgenetic pages 1-4, iwasa2014retinitispigmentosaand pages 2-3, hoshino1999ataxiawithisolated pages 22-23) Lifelong high-dose oral vitamin E replacement. Reported recommendations/examples: 800–1500 mg/day or about 40 mg/kg/day in children; case regimens include 800 mg/day, 400 mg three times daily, 1,200 IU/day, and 2,000 units/day. Early treatment can halt progression, stabilize disease, and sometimes improve established neurologic abnormalities; delayed treatment may leave persistent proprioceptive/gait deficits (esmer2013clinicalandmolecular pages 2-4, vera2021pearls&oysters pages 1-5, holla2024geneticallyprovenataxia pages 1-2, zhang2021clinicalandgenetic pages 1-4, iwasa2014retinitispigmentosaand pages 2-3, cavalier1998ataxiawithisolated pages 7-8, mariotti2004ataxiawithisolated pages 7-10) Cavalier 1998, Am J Hum Genet, DOI: https://doi.org/10.1086/301699 (cavalier1998ataxiawithisolated pages 7-8); Hoshino 1999, Ann Neurol, DOI: https://doi.org/10.1002/1531-8249(199906)45:6<809::aid-ana19>3.0.co;2-9 (hoshino1999ataxiawithisolated pages 22-23); Iwasa 2014, J Neurol Sci, DOI: https://doi.org/10.1016/j.jns.2014.07.001 (iwasa2014retinitispigmentosaand pages 2-3); Holla 2024, J Mov Disord, DOI: https://doi.org/10.14802/jmd.23227 (holla2024geneticallyprovenataxia pages 1-2)

Table: This table condenses the evidence-backed core facts for familial isolated vitamin E deficiency / AVED, including identifiers, genetics, phenotype, variants, and treatment. It is useful as a quick reference for knowledge-base population while limiting claims to those explicitly present in the provided snippets.

URLs and publication dates (from retrieved evidence)

Notes on limitations of this tool-based report

  • Ontology identifiers beyond OMIM (e.g., Orphanet, MONDO, MeSH, ICD-10/11) could not be verified from the retrieved full-text evidence in this run and are therefore omitted rather than inferred.
  • Population prevalence/incidence and population allele frequencies (gnomAD) were not present in the retrieved evidence snippets.
  • Model organism evidence was not present in the retrieved evidence snippets used for citation; therefore it is not summarized here.

References

  1. (holla2024geneticallyprovenataxia pages 1-2): Vikram V. Holla, Sandeep Gurram, Sneha D. Kamath, Gautham Arunachal, Nitish Kamble, Ravi Yadav, and Pramod Kumar Pal. Genetically proven ataxia with vitamin e deficiency with predominant cervicobrachial dystonic presentation: a case report from india. Journal of Movement Disorders, 17:220-222, Apr 2024. URL: https://doi.org/10.14802/jmd.23227, doi:10.14802/jmd.23227. This article has 0 citations and is from a peer-reviewed journal.

  2. (hoshino1999ataxiawithisolated pages 22-23): Masataka Hoshino, Naoki Masuda, Yasuhiko Ito, Miho Murata, Jun Goto, Masaki Sakurai, and Ichiro Kanazawa. Ataxia with isolated vitamin e deficiency: a japanese family carrying a novel mutation in the α‐tocopherol transfer protein gene. Annals of Neurology, 45:809-812, Jun 1999. URL: https://doi.org/10.1002/1531-8249(199906)45:6<809::aid-ana19>3.0.co;2-9, doi:10.1002/1531-8249(199906)45:6<809::aid-ana19>3.0.co;2-9. This article has 38 citations and is from a highest quality peer-reviewed journal.

  3. (zhang2021clinicalandgenetic pages 1-4): Linwei Zhang, Xiangfei Zhang, Pu Lv, and Dantao Peng. Clinical and genetic study of ataxia with vitamin e deficiency. ArXiv, Feb 2021. URL: https://doi.org/10.21203/rs.3.rs-175944/v1, doi:10.21203/rs.3.rs-175944/v1. This article has 0 citations.

  4. (cavalier1998ataxiawithisolated pages 7-8): Laurent Cavalier, Karim Ouahchi, Herbert J. Kayden, Stephano Di Donato, Laurence Reutenauer, Jean-Louis Mandel, and Michel Koenig. Ataxia with isolated vitamin e deficiency: heterogeneity of mutations and phenotypic variability in a large number of families. American journal of human genetics, 62 2:301-10, Feb 1998. URL: https://doi.org/10.1086/301699, doi:10.1086/301699. This article has 383 citations and is from a highest quality peer-reviewed journal.

  5. (iwasa2014retinitispigmentosaand pages 2-3): Kazuo Iwasa, Keisuke Shima, Kiyonobu Komai, Yoichiro Nishida, Takanori Yokota, and Masahito Yamada. Retinitis pigmentosa and macular degeneration in a patient with ataxia with isolated vitamin e deficiency with a novel c.717 del c mutation in the ttpa gene. Journal of the neurological sciences, 345 1-2:228-30, Oct 2014. URL: https://doi.org/10.1016/j.jns.2014.07.001, doi:10.1016/j.jns.2014.07.001. This article has 28 citations and is from a peer-reviewed journal.

  6. (esmer2013clinicalandmolecular pages 2-4): C Esmer, AS Martínez, and ER Palomo. Clinical and molecular findings in a patient with ataxia with vitamin e deficiency, homozygous for the c. 205-1g› c mutation in the ttpa gene. Unknown journal, 2013.

  7. (stoiloudis2022vitaminedeficiency pages 42-44): P Stoiloudis, AN Terzakis, and N Smyrni. Vitamin e deficiency: clinical characteristics, diagnosis and management. Unknown journal, 2022.

  8. (hoshino1999ataxiawithisolated pages 23-24): Masataka Hoshino, Naoki Masuda, Yasuhiko Ito, Miho Murata, Jun Goto, Masaki Sakurai, and Ichiro Kanazawa. Ataxia with isolated vitamin e deficiency: a japanese family carrying a novel mutation in the α‐tocopherol transfer protein gene. Annals of Neurology, 45:809-812, Jun 1999. URL: https://doi.org/10.1002/1531-8249(199906)45:6<809::aid-ana19>3.0.co;2-9, doi:10.1002/1531-8249(199906)45:6<809::aid-ana19>3.0.co;2-9. This article has 38 citations and is from a highest quality peer-reviewed journal.

  9. (mariotti2004ataxiawithisolated pages 7-10): C. Mariotti, C. Gellera, M. Rimoldi, R. Mineri, G. Uziel, G. Zorzi, D. Pareyson, G. Piccolo, D. Gambi, S. Piacentini, F. Squitieri, R. Capra, B. Castellotti, and S. Di Donato. Ataxia with isolated vitamin e deficiency: neurological phenotype, clinical follow-up and novel mutations in ttpagene in italian families. Neurological Sciences, 25:130-137, Jul 2004. URL: https://doi.org/10.1007/s10072-004-0246-z, doi:10.1007/s10072-004-0246-z. This article has 181 citations and is from a peer-reviewed journal.

  10. (vera2021pearls&oysters pages 1-5): Alonso Zea Vera, Wei Liu, Cameron Thomas, and Donald L. Gilbert. Pearls & oy-sters: a novel presentation of ataxia with vitamin e deficiency caused by ttpa gene mutation. Jan 2021. URL: https://doi.org/10.1212/wnl.0000000000010853, doi:10.1212/wnl.0000000000010853. This article has 5 citations and is from a highest quality peer-reviewed journal.

  11. (iwasa2014retinitispigmentosaand pages 1-2): Kazuo Iwasa, Keisuke Shima, Kiyonobu Komai, Yoichiro Nishida, Takanori Yokota, and Masahito Yamada. Retinitis pigmentosa and macular degeneration in a patient with ataxia with isolated vitamin e deficiency with a novel c.717 del c mutation in the ttpa gene. Journal of the neurological sciences, 345 1-2:228-30, Oct 2014. URL: https://doi.org/10.1016/j.jns.2014.07.001, doi:10.1016/j.jns.2014.07.001. This article has 28 citations and is from a peer-reviewed journal.

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