Home / Deep Research / Free Sialic Acid Storage Disease

Free Sialic Acid Storage Disease

1. Disease Information

2026-05-10
Falcon MONDO:0019366 Model: Edison Scientific Literature 32 citations

1. Disease Information

1.1 What is the disease?

FSASD is a group of lysosomal storage disorders in which defective lysosomal export of free sialic acid results in abnormal retention of free sialic acid in lysosomes and elevated free sialic acid in urine (often also CSF) with a clinical spectrum ranging from Salla disease to ISSD. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2, aulanko2023psychiatricsymptomsin pages 1-2, hu2023themolecularmechanism pages 1-2, verheijen1999anewgene pages 1-3)

1.2 Key identifiers

1.3 Synonyms / alternative names used in the literature

1.4 Evidence source type

Most clinical characterization derives from aggregated case reports/case series and literature-based cohorts (e.g., cross-sectional natural history synthesis) rather than EHR-based population studies. (zielonka2019acrosssectionalquantitative pages 3-4, zielonka2019acrosssectionalquantitative pages 2-3)

2. Etiology

2.1 Disease causal factors

Primary cause (genetic, Mendelian): biallelic pathogenic variants in SLC17A5, encoding the lysosomal membrane transporter sialin, cause FSASD. (aulanko2023psychiatricsymptomsin pages 1-2, hu2023themolecularmechanism pages 1-2, verheijen1999anewgene pages 1-3)

Foundational discovery: The causal gene was identified in 1999: “A new gene, encoding an anion transporter, is mutated in sialic acid storage diseases,” establishing SLC17A5/sialin as the disease gene. (verheijen1999anewgene pages 1-1)

2.2 Risk factors

  • Genetic risk: inheritance is autosomal recessive; Finnish founder effect is prominent for Salla disease.

  • In Finland, “More than 90% of Finnish SD patients are homozygous for the pathogenic SLC17A5 c.115C>T; p.(Arg39Cys) … founder variant.” (aulanko2023psychiatricsymptomsin pages 1-2)

  • Environmental risk factors / protective factors / gene–environment: no specific environmental modifiers were identified in the retrieved sources; disease is primarily monogenic with severity driven largely by genotype and biochemical burden. Genotype–phenotype correlation has been discussed historically. (aula2000thespectrumof pages 9-9, aulanko2023psychiatricsymptomsin pages 1-2)

3. Phenotypes

3.1 Core phenotype spectrum (human)

Salla disease (milder end of spectrum): intellectual disability, ataxia, athetosis, nystagmus, and CNS demyelination/dysmyelination, with typical symptom detection in infancy. * “Salla disease (SD) is a rare lysosomal storage disorder characterised by intellectual disability ataxia, athetosis, nystagmus, and central nervous system demyelination.” (aulanko2023psychiatricsymptomsin pages 1-2) * “The first symptoms are typically detected between the ages of 3–12 months.” (aulanko2023psychiatricsymptomsin pages 1-2)

ISSD (severe infantile form): multisystem involvement with visceromegaly and coarse facial features; poor survival. * ISSD is described as “clinically distinct and very serious… visceromegaly, coarse facial features, failure to thrive, and early death.” (valianpour2004quantificationoffree pages 1-2)

Neuroimaging phenotype: in FSASD/Salla disease, MRI frequently shows hypomyelination and atrophy. * In undiagnosed leukodystrophy presentations, symptoms are “associated with diffuse supratentorial hypomyelination, thin corpus callosum, and cortical and cerebellar atrophy.” (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2) * In a literature cohort, MRI abnormalities included brain atrophy (19.8%), hypomyelination (19%), and corpus callosum thinning (13.8%). (zielonka2019acrosssectionalquantitative pages 4-6)

3.2 Psychiatric/behavioral features (recent quantitative data)

A 24-patient Salla disease cohort review found psychiatric symptoms are common: * “Psychiatric symptoms were frequently associated with SD (10/24, 42%),” with sleeping disorders 8/24 (32%), aggressive behavior/restlessness 6/24 (25%), and off-label antipsychotic medication 4/24 (17%). (aulanko2023psychiatricsymptomsin pages 1-2)

3.3 Suggested HPO terms (non-exhaustive; for knowledge-base mapping)

3.4 Quality-of-life impact

Direct QoL instrument data (EQ-5D/SF-36/PROMIS) were not located in retrieved texts; functional dependence and behavioral symptoms indicate high caregiver burden, and some individuals require assistance with activities of daily living. (aulanko2023psychiatricsymptomsin pages 1-2)

4. Genetic / Molecular Information

4.1 Causal gene

4.2 Pathogenic variants and variant classes (examples from primary sources)

Because ClinVar/gnomAD/HGMD were not directly queried via tools in this run, allele frequencies and ClinVar pathogenicity classifications are not provided here; they should be filled from ClinVar/gnomAD during curation.

4.3 Functional consequences

Pathogenic SLC17A5 variants impair lysosomal export of free sialic acid, causing storage. * FSASD are characterized by “enlarged cellular lysosomes and elevated levels of free sialic acids in urine.” (hu2023themolecularmechanism pages 1-2)

Recent structural work provides mechanistic explanations for pathogenic mutations: * 2023 cryo-EM work: “By mapping known pathogenic mutations, we provide mechanistic explanations for corresponding functional defects.” (hu2023themolecularmechanism pages 1-2)

4.4 Suggested GO terms (biological process; examples)

4.5 Suggested GO cellular component terms

5. Environmental Information

No disease-specific environmental, lifestyle, or infectious triggers/protectors were identified in the retrieved sources; FSASD is primarily a monogenic lysosomal transporter disorder. (aulanko2023psychiatricsymptomsin pages 1-2, verheijen1999anewgene pages 1-3)

6. Mechanism / Pathophysiology

6.1 Core causal chain (current understanding)

  1. Biallelic SLC17A5 variants →
  2. Defective sialin function (lysosomal sialic acid exporter / proton-coupled transporter) →
  3. Retention/accumulation of free sialic acid in lysosomes, with elevated free sialic acid in urine and/or CSF →
  4. Downstream CNS pathology including hypomyelination, thin corpus callosum, cortical/cerebellar atrophy, and progressive neurodevelopmental impairment. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2, hu2023themolecularmechanism pages 1-2, schmiege2024structureandinhibition pages 1-2)

6.2 Biochemical abnormalities and diagnostic markers

6.3 Recent mechanistic developments (prioritize 2023–2024)

2023 (Science Advances; published 20 Jan 2023; URL in BibTeX): first high-resolution human SLC17 family structure. * Abstract quote: “we present the structure of human Sialin… determined by cryo–electron microscopy, representing the first high-resolution structure of any human SLC17 member.” (hu2023themolecularmechanism pages 1-2) * Abstract quote: “The H+ coupling/sensing requires two highly conserved Glu residues (E171 and E175)…” (hu2023themolecularmechanism pages 1-2)

2024 (Nature Communications; accepted 3 May 2024; DOI URL): multiple conformational states and inhibitor binding. * Abstract quote: “we present the cryogenic electron-microscopy structures of human Sialin: apo cytosol-open, apo lumen-open, NAAG–bound, and inhibitor–bound.” (schmiege2024structureandinhibition pages 1-2) * The work identifies an inhibitor-binding mode (“Sialin inhibitor Fmoc-Leu-OH”) and residues governing substrate recognition, supporting structure-guided drug discovery. (schmiege2024structureandinhibition pages 1-2)

6.4 Molecular profiling (available evidence)

Although beyond 2024, recent disease-modeling indicates glycosphingolipid (GSL) metabolism perturbation in patient iPSC-derived neural cells with striking astrocyte changes. * Free sialic acid elevations vs controls were reported across cell types, including mature astrocytes (830% of healthy donors). (sabir2025lysosomalfreesialic pages 2-3)

6.5 Suggested cell types (CL terms; examples)

7. Anatomical Structures Affected

7.1 Organ/system level

Primary: central nervous system (brain white matter, cerebellum) with hypomyelination and atrophy. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2)

Secondary/multisystem (especially ISSD): visceromegaly/hepatosplenomegaly and coarse facial features. (valianpour2004quantificationoffree pages 1-2, verheijen1999anewgene pages 1-1)

7.2 Suggested UBERON terms (examples)

7.3 Subcellular localization

Lysosomal lumen/membrane involvement is central (lysosomal free sialic acid accumulation; lysosomal membrane transporter). (schmiege2024structureandinhibition pages 1-2)

8. Temporal Development

8.1 Onset

In a large literature-based cohort (postnatally diagnosed), median onset was 0.17 years (~2 months). (zielonka2019acrosssectionalquantitative pages 1-2)

In Salla disease specifically, first symptoms are “typically detected between the ages of 3–12 months.” (aulanko2023psychiatricsymptomsin pages 1-2)

8.2 Progression and disease course

FSASD demonstrates a continuous phenotypic spectrum; ISSD is rapidly progressive with early mortality, while Salla disease can allow survival into adulthood. (hu2023themolecularmechanism pages 1-2, schmiege2023structuresandmechanisms pages 31-36, zielonka2019acrosssectionalquantitative pages 1-2)

8.3 Critical periods

Prenatal and perinatal manifestations occur in a substantial subset: * Hydrops fetalis occurred as the first clinical sign in 20.7% of cases in the literature cohort. (zielonka2019acrosssectionalquantitative pages 3-4, zielonka2019acrosssectionalquantitative pages 2-3)

9. Inheritance and Population

9.1 Inheritance

Autosomal recessive inheritance is consistently reported for Salla disease/FSASD. * “Salla disease… is a rare autosomal recessive lysosomal storage disorder…” (aulanko2023psychiatricsymptomsin pages 1-2)

9.2 Epidemiology

Robust prevalence/incidence estimates were not retrieved from Orphanet/registry pages in this run; however: * Literature synthesis notes Orphanet-listed case counts (~130 known cases) and panethnic distribution. (zielonka2019acrosssectionalquantitative pages 1-2, zielonka2019acrosssectionalquantitative pages 4-6) * Salla disease is enriched in Finland (“Finnish disease heritage”), with the p.Arg39Cys founder variant accounting for >90% of Finnish SD cases. (aulanko2023psychiatricsymptomsin pages 1-2)

9.3 Sex ratio and demographics

A Finnish hospital-based cohort of 24 Salla disease patients was 75% male (18/24). This may reflect ascertainment/registry bias rather than true sex skew given autosomal recessive inheritance. (aulanko2023psychiatricsymptomsin pages 1-2)

10. Diagnostics

10.1 Biochemical testing (real-world implementations)

Urine free sialic acid quantification is central. * A 2004 Clinical Chemistry method paper states: “Defective free sialic acid transport can be established by quantification of free sialic acid in urine.” (valianpour2004quantificationoffree pages 1-2) * Age-dependent control ranges were established (n=72 controls). For example, ages 0–1 year: mean 31.3 mmol/mol creatinine (range 0.7–56.9; n=20). (valianpour2004quantificationoffree pages 1-2) * In three SSD patients aged 1.2, 3.9, 12 years, urinary free sialic acid concentrations were 111.5, 54.2, and 36.1 mmol/mol creatinine. (valianpour2004quantificationoffree pages 1-2)

CSF/urine screening in leukodystrophy workups: * In a cross-sectional leukodystrophy cohort (41 patients with hypomyelination of unknown etiology), 6/41 had increased free sialic acid in CSF or urine and all had SLC17A5 mutations. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2)

CSF NAAG as supportive biomarker: * “H-NMRS revealed an increase of N-acetylaspartylglutamate in the CSF of all patients with SLC17A5 mutation (range 13–114 µmol/L, reference <12 µmol/L).” (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2)

Visual evidence for the Mochel et al. biochemical table and MR spectrum is available in the extracted figure/table crops. (mochel2010elevatedcsfnacetylaspartylglutamate media ffd5dd78, mochel2010elevatedcsfnacetylaspartylglutamate media de78242d)

10.2 Genetic testing

Diagnosis is confirmed by identifying biallelic pathogenic variants in SLC17A5. * Foundational mutation discovery and examples (including R39C) were reported in 1999, with a mutation table for SD and ISSD. (verheijen1999anewgene pages 1-3)

For leukodystrophy presentations, genome/exome-first strategies are increasingly implemented in clinical programs that include Salla disease among target conditions. * Clinical WGS study (LeukoSEQ; completed) enrolled 236 participants; interim analysis described diagnostic efficacy of WGS+standard care at 26/34 (76.5%; 95% CI 58.8–89.3%) within <4 months and faster time to diagnosis than standard care alone. (NCT02699190 chunk 1)

10.3 Differential diagnosis

Not comprehensively enumerated in retrieved sources; key differentials in hypomyelinating leukodystrophy evaluations include other genetic white-matter disorders. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2, NCT02699190 chunk 1)

10.4 Screening

Not a standard newborn screening condition in the retrieved sources; prenatal presentation (hydrops fetalis) supports consideration in prenatal/NIHF workups with biochemical/genetic testing. (zielonka2019acrosssectionalquantitative pages 3-4)

11. Outcome / Prognosis

A 2019 quantitative natural-history analysis (116 published cases; 106 postnatally diagnosed) reported: * Median survival 11 years (postnatally diagnosed subset). (zielonka2019acrosssectionalquantitative pages 3-4, zielonka2019acrosssectionalquantitative pages 2-3) * Median age at diagnosis 3 years and median diagnostic delay 2.5 years (subset N=90 with data). (zielonka2019acrosssectionalquantitative pages 3-4, zielonka2019acrosssectionalquantitative pages 2-3)

Biomarker severity correlates with outcome: * Urinary free sialic acid excretion <6.37-fold of normal (and fibroblast storage <7.37-fold) was associated with significantly longer survival in recursive partitioning analyses. (zielonka2019acrosssectionalquantitative pages 3-4)

12. Treatment

12.1 Current standard of care

No disease-modifying therapy was identified in the retrieved sources; management is primarily symptomatic/supportive. * A lysosomal transporter review/thesis summary notes: “Currently, there are only symptomatic treatments for these FSASDs.” (schmiege2023structuresandmechanisms pages 31-36) * 2019 natural-history synthesis reported no clinical trials or orphan drug designations as of 31 Dec 2017. (zielonka2019acrosssectionalquantitative pages 1-2, zielonka2019acrosssectionalquantitative pages 4-6)

12.2 Experimental/forward-looking approaches (expert analysis)

Structural biology now enables rational exploration of small-molecule modulation and mutation-specific rescue. * 2024 Nature Communications work reports an “inhibitor–bound” structure and identifies a sialin inhibitor (Fmoc-Leu-OH), providing a foothold for structure-guided ligand development (though not yet a therapy). (schmiege2024structureandinhibition pages 1-2)

12.3 Suggested MAXO terms (examples)

13. Prevention

Primary prevention is not applicable in the usual sense for a recessive Mendelian disorder; prevention focuses on genetic counseling and reproductive options. * Given autosomal recessive inheritance, family-based carrier testing and prenatal diagnosis are standard preventive strategies, especially in founder populations; prenatal/pregnancy presentations (hydrops fetalis) reinforce this clinical need. (aulanko2023psychiatricsymptomsin pages 1-2, zielonka2019acrosssectionalquantitative pages 3-4)

14. Other Species / Natural Disease

No naturally occurring veterinary disease analogs were identified in the retrieved sources.

15. Model Organisms

A sialin-deficient mouse model is referenced in natural-history synthesis: * “sialin-/- mice show progressive leukoencephalopathy with decreased myelinated axons, oligodendrocyte apoptosis… coordination defects, seizures, and premature death.” (zielonka2019acrosssectionalquantitative pages 1-2, zielonka2019acrosssectionalquantitative pages 4-6)

Cellular models include patient-derived iPSC neural differentiation platforms (two FSASD lines vs two controls) enabling mechanistic studies of cell-type vulnerability (notably astrocytes). (sabir2025lysosomalfreesialic pages 1-2, sabir2025lysosomalfreesialic pages 2-3)

Notes on evidence limitations (important for knowledge-base curation)

  • PMIDs were not available in the tool-returned full texts for most citations in this run; DOIs/URLs and publication timing are provided from the retrieved PDFs/records. Curators should augment with PMIDs from PubMed.
  • MONDO/Orphanet/MeSH/ICD identifiers were not retrievable from the accessible texts; these should be populated directly from the corresponding ontology/database pages.

Key primary sources (with URLs and dates as available from retrieved texts)

References

  1. (aulanko2023psychiatricsymptomsin pages 1-2): Ida Aulanko, Elisa Rahikkala, and Jukka Moilanen. Psychiatric symptoms in salla disease. European Child & Adolescent Psychiatry, 32:2043-2047, Jul 2023. URL: https://doi.org/10.1007/s00787-022-02031-5, doi:10.1007/s00787-022-02031-5. This article has 4 citations and is from a domain leading peer-reviewed journal.

  2. (hu2023themolecularmechanism pages 1-2): Wenxin Hu, Congwu Chi, Kunhua Song, and Hongjin Zheng. The molecular mechanism of sialic acid transport mediated by sialin. Science Advances, Jan 2023. URL: https://doi.org/10.1126/sciadv.ade8346, doi:10.1126/sciadv.ade8346. This article has 27 citations and is from a highest quality peer-reviewed journal.

  3. (schmiege2024structureandinhibition pages 1-2): Philip Schmiege, Linda Donnelly, Nadia Elghobashi-Meinhardt, Chia-Hsueh Lee, and Xiaochun Li. Structure and inhibition of the human lysosomal transporter sialin. Nature Communications, May 2024. URL: https://doi.org/10.1038/s41467-024-48535-3, doi:10.1038/s41467-024-48535-3. This article has 13 citations and is from a highest quality peer-reviewed journal.

  4. (schmiege2023structuresandmechanisms pages 31-36): PFP Schmiege. Structures and mechanisms of lysosomal transporters. Unknown journal, 2023.

  5. (mochel2010elevatedcsfnacetylaspartylglutamate pages 1-2): F. Mochel, U.F.H. Engelke, J. Barritault, B. Yang, N. H. McNeill, J. N. Thompson, A. Vanderver, N. I. Wolf, M. A. Willemsen, F. W. Verheijen, F. Seguin, R. A. Wevers, and R. Schiffmann. Elevated csf n-acetylaspartylglutamate in patients with free sialic acid storage diseases. Neurology, 74:302-305, Jan 2010. URL: https://doi.org/10.1212/wnl.0b013e3181cbcdc4, doi:10.1212/wnl.0b013e3181cbcdc4. This article has 32 citations and is from a highest quality peer-reviewed journal.

  6. (valianpour2004quantificationoffree pages 1-2): Fredoen Valianpour, Nicolaas G G M Abeling, Marinus Duran, Jan G M Huijmans, and Willem Kulik. Quantification of free sialic acid in urine by hplc-electrospray tandem mass spectrometry: a tool for the diagnosis of sialic acid storage disease. Clinical chemistry, 50 2:403-9, Feb 2004. URL: https://doi.org/10.1373/clinchem.2003.027169, doi:10.1373/clinchem.2003.027169. This article has 58 citations and is from a highest quality peer-reviewed journal.

  7. (verheijen1999anewgene pages 1-3): Frans W. Verheijen, Elly Verbeek, Nina Aula, Cecile E.M.T. Beerens, Adrie C. Havelaar, Marijke Joosse, Leena Peltonen, Pertti Aula, Hans Galjaard, Peter J. van der Spek, and Grazia M.S. Mancini. A new gene, encoding an anion transporter, is mutated in sialic acid storage diseases. Nature Genetics, 23:462-465, Dec 1999. URL: https://doi.org/10.1038/70585, doi:10.1038/70585. This article has 351 citations and is from a highest quality peer-reviewed journal.

  8. (verheijen1999anewgene pages 1-1): Frans W. Verheijen, Elly Verbeek, Nina Aula, Cecile E.M.T. Beerens, Adrie C. Havelaar, Marijke Joosse, Leena Peltonen, Pertti Aula, Hans Galjaard, Peter J. van der Spek, and Grazia M.S. Mancini. A new gene, encoding an anion transporter, is mutated in sialic acid storage diseases. Nature Genetics, 23:462-465, Dec 1999. URL: https://doi.org/10.1038/70585, doi:10.1038/70585. This article has 351 citations and is from a highest quality peer-reviewed journal.

  9. (mochel2010elevatedcsfnacetylaspartylglutamate media ffd5dd78): F. Mochel, U.F.H. Engelke, J. Barritault, B. Yang, N. H. McNeill, J. N. Thompson, A. Vanderver, N. I. Wolf, M. A. Willemsen, F. W. Verheijen, F. Seguin, R. A. Wevers, and R. Schiffmann. Elevated csf n-acetylaspartylglutamate in patients with free sialic acid storage diseases. Neurology, 74:302-305, Jan 2010. URL: https://doi.org/10.1212/wnl.0b013e3181cbcdc4, doi:10.1212/wnl.0b013e3181cbcdc4. This article has 32 citations and is from a highest quality peer-reviewed journal.

  10. (hu2023themolecularmechanism pages 6-7): Wenxin Hu, Congwu Chi, Kunhua Song, and Hongjin Zheng. The molecular mechanism of sialic acid transport mediated by sialin. Science Advances, Jan 2023. URL: https://doi.org/10.1126/sciadv.ade8346, doi:10.1126/sciadv.ade8346. This article has 27 citations and is from a highest quality peer-reviewed journal.

  11. (NCT02699190 chunk 1): Adeline Vanderver, MD. LeukoSEQ: Whole Genome Sequencing as a First-Line Diagnostic Tool for Leukodystrophies. Children's Hospital of Philadelphia. 2017. ClinicalTrials.gov Identifier: NCT02699190

  12. (NCT03047369 chunk 1): Adeline Vanderver, MD. The Myelin Disorders Biorepository Project. Children's Hospital of Philadelphia. 2016. ClinicalTrials.gov Identifier: NCT03047369

  13. (zielonka2019acrosssectionalquantitative pages 3-4): Matthias Zielonka, Sven F. Garbade, Stefan Kölker, Georg F. Hoffmann, and Markus Ries. A cross-sectional quantitative analysis of the natural history of free sialic acid storage disease—an ultra-orphan multisystemic lysosomal storage disorder. Genetics in Medicine, 21:347-352, Feb 2019. URL: https://doi.org/10.1038/s41436-018-0051-3, doi:10.1038/s41436-018-0051-3. This article has 31 citations and is from a highest quality peer-reviewed journal.

  14. (zielonka2019acrosssectionalquantitative pages 2-3): Matthias Zielonka, Sven F. Garbade, Stefan Kölker, Georg F. Hoffmann, and Markus Ries. A cross-sectional quantitative analysis of the natural history of free sialic acid storage disease—an ultra-orphan multisystemic lysosomal storage disorder. Genetics in Medicine, 21:347-352, Feb 2019. URL: https://doi.org/10.1038/s41436-018-0051-3, doi:10.1038/s41436-018-0051-3. This article has 31 citations and is from a highest quality peer-reviewed journal.

  15. (aula2000thespectrumof pages 9-9): Nina Aula, Pirjo Salomäki, Ritva Timonen, Frans Verheijen, Grazia Mancini, Jan-Eric Månsson, Pertti Aula, and Leena Peltonen. The spectrum of slc17a5-gene mutations resulting in free sialic acid-storage diseases indicates some genotype-phenotype correlation. American journal of human genetics, 67 4:832-40, Oct 2000. URL: https://doi.org/10.1086/303077, doi:10.1086/303077. This article has 144 citations and is from a highest quality peer-reviewed journal.

  16. (zielonka2019acrosssectionalquantitative pages 4-6): Matthias Zielonka, Sven F. Garbade, Stefan Kölker, Georg F. Hoffmann, and Markus Ries. A cross-sectional quantitative analysis of the natural history of free sialic acid storage disease—an ultra-orphan multisystemic lysosomal storage disorder. Genetics in Medicine, 21:347-352, Feb 2019. URL: https://doi.org/10.1038/s41436-018-0051-3, doi:10.1038/s41436-018-0051-3. This article has 31 citations and is from a highest quality peer-reviewed journal.

  17. (sabir2025lysosomalfreesialic pages 2-3): M. Sabir, V. Jovanovic, Seungmi Ryu, Chaitali Sen, Pinar Ormanoglu, Laura Pollard, Richard Steet, William A. Gahl, M. Huizing, Carlos A. Tristan, Frances M. Platt, and M. Malicdan. Lysosomal free sialic acid storage disorder ipsc-derived neural cells display altered glycosphingolipid metabolism. Scientific Reports, Aug 2025. URL: https://doi.org/10.1038/s41598-025-12682-4, doi:10.1038/s41598-025-12682-4. This article has 2 citations and is from a peer-reviewed journal.

  18. (zielonka2019acrosssectionalquantitative pages 1-2): Matthias Zielonka, Sven F. Garbade, Stefan Kölker, Georg F. Hoffmann, and Markus Ries. A cross-sectional quantitative analysis of the natural history of free sialic acid storage disease—an ultra-orphan multisystemic lysosomal storage disorder. Genetics in Medicine, 21:347-352, Feb 2019. URL: https://doi.org/10.1038/s41436-018-0051-3, doi:10.1038/s41436-018-0051-3. This article has 31 citations and is from a highest quality peer-reviewed journal.

  19. (mochel2010elevatedcsfnacetylaspartylglutamate media de78242d): F. Mochel, U.F.H. Engelke, J. Barritault, B. Yang, N. H. McNeill, J. N. Thompson, A. Vanderver, N. I. Wolf, M. A. Willemsen, F. W. Verheijen, F. Seguin, R. A. Wevers, and R. Schiffmann. Elevated csf n-acetylaspartylglutamate in patients with free sialic acid storage diseases. Neurology, 74:302-305, Jan 2010. URL: https://doi.org/10.1212/wnl.0b013e3181cbcdc4, doi:10.1212/wnl.0b013e3181cbcdc4. This article has 32 citations and is from a highest quality peer-reviewed journal.

  20. (sabir2025lysosomalfreesialic pages 1-2): M. Sabir, V. Jovanovic, Seungmi Ryu, Chaitali Sen, Pinar Ormanoglu, Laura Pollard, Richard Steet, William A. Gahl, M. Huizing, Carlos A. Tristan, Frances M. Platt, and M. Malicdan. Lysosomal free sialic acid storage disorder ipsc-derived neural cells display altered glycosphingolipid metabolism. Scientific Reports, Aug 2025. URL: https://doi.org/10.1038/s41598-025-12682-4, doi:10.1038/s41598-025-12682-4. This article has 2 citations and is from a peer-reviewed journal.