ORPHA:397618
Foveal hypoplasia-optic nerve decussation defect-anterior segment dysgenesis syndrome
Also known as: FHONDA syndrome
Query health: suspect — Only one of 3 strategies returned hits (phrase).
Publications
42
47.5th percentile
Trials
0
Interventional, condition-specific
Researchers
319
Distinct authors in sample
Gene link
SLC38A8
Definitive
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare, genetic, eye disease characterized by foveal hypoplasia, optic nerve misrouting with an increased number of axons decussating at the optic chiasm and innervating the contralateral cortex, and posterior embryotoxon or Axenfeld anomaly (indicating anterior segment dysgenesis), in the absence of albinism. Patients present nystagmus, decreased visual acuity, refractive errors and, ocassionally, strabismus. Microphthalmia and retinochoroidal coloboma may also be associated.
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0012216
- MeSH:C563774
- OMIM:609218
- UMLS:C3807873
Additional Mondo synonyms (3)
foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome · foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis · foveal hypoplasia type 2
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Definitive — SLC38A8
- LiteraturePresent
42 matched papers (36 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Yes — we know a specific gene responsible (SLC38A8).
GenCC classification: Definitive.
Phenotypes (Monarch / HPO)
Not enriched in this build — Monarch phenotype joins were not run for this record.
Animal models (Monarch / Alliance)
Not enriched in this build.
Literature
Is anyone studying this?
42
42 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
42 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).
36 in the last 10 years · high confidence · 47.5th percentile (publications denominator)
Phrase hits: 42 · MeSH hits: 0
Who's working on it?
319
Distinct author names in 42 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Al-Araimi M4 papers · 2014
National Genetic Centre, Royal Hospital, Muscat, Oman;
Papers in Europe PMC - 02
- 03Houshmand M4 papers · 2014
National Institute for Genetic Engineering & Biotechnology, Tehran, Iran;
Papers in Europe PMC - 04
- 05van Genderen MM4 papers · 2022
Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.
Papers in Europe PMC - 06Al-Kharusi M3 papers · 2014
National Genetic Centre, Royal Hospital, Muscat, Oman.
Papers in Europe PMC - 07Arveiler B3 papers · 2025
Maladies Rares: Génétique et Métabolisme (MRGM), Inserm U1211, University of Bordeaux, Bordeaux, France.
Papers in Europe PMC - 08Aryani O3 papers · 2014
Department of Medical Genetics, Special Medical Center, Tehran, Iran;
Papers in Europe PMC - 09Bradbury J3 papers · 2014
Human Genome Sequencing Center, Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
Papers in Europe PMC - 10
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 27 July 2026
No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.
high confidence · 36.5th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
Broader category foveal hypoplasia also has no matched interventional trial. See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Broader category: foveal hypoplasia
0
Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.
Parent-category matching found a broader label but no interventional trials under it. How we count trials.
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Foveal hypoplasia-optic nerve decussation defect-anterior segment dysgenesis syndrome" OR "FHONDA syndrome" OR "foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome" OR "foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis" OR "foveal hypoplasia type 2"
MeSH descriptor terms unioned into the query: Foveal Hypoplasia and Anterior Segment Dysgenesis
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Foveal hypoplasia-optic nerve decussation defect-anterior segment dysgenesis syndrome" OR "FHONDA syndrome" OR "foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome" OR "foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis" OR "foveal hypoplasia type 2" OR "Foveal Hypoplasia and Anterior Segment Dysgenesis" OR "SLC38A8"
Recall-expansion terms: SLC38A8
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"foveal hypoplasia"
Query health: suspect — strategies attempted: phrase, mesh, recall-expansion; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-27T15:11:50.480Z