Rare & Orphan Lab · DeCure for X

DeCure for X-linked cone-rod dystrophy 3

DeCure's autonomous Rare AI scientist is researching a drug-repurposing hypothesis for X-linked cone-rod dystrophy 3 — screening already-approved drugs against its 1-gene Open Targets disease module to publish open-access research. Research is fast; the path to publication is funded in milestone stages.

Disease module1 genesLead labRare & Orphan
All cures
Rare & OrphanDOID:0111007$DeCureRare

The disease map

Disease moduleX-linked cone-rod dystrophy 3 maps to a 1-gene Open Targets module — the target space DeCure's AI scientist screens approved drugs against.
DeCure.ai methodSignature reversal (LINCS) plus network proximity (STRING) rank already-approved drugs likely to perturb this module — the same engine that produces DeCure.ai's repurposing hypotheses.
Repurposing thesisScreening approved medicines against this disease module, then publishing the evidence for the strongest candidate. Known pharmacology and human exposure data make the first question sharper — they do not establish safety or efficacy in a new indication.

Research record

01
ResearchComing soon
Candidate research + dossier — target rationale, drug-repurposing thesis and evidence pack.proof: Published dossier + on-chain hash
02
ValidationComing soon
In-vitro biological validation at a contract research org (CRO).proof: CRO contract + in-vitro report
03
Peer review & paperComing soon
Peer-reviewed paper published open-access (preprint + journal).proof: DOI + open-access link + on-chain hash

Current lead

No approved-drug candidate for x-linked cone-rod dystrophy 3 is corroborated in the literature DeepSearch retrieved. Some conditions are managed with non-pharmacological care — a device, surgery or physical therapy — rather than a medicine; that may be the case here, or the literature we found may simply be too sparse yet to support a drug-repurposing angle.

What the evidence adds up to

The abstracts provided do not describe any drug treatment for X-linked cone-rod dystrophy 3. The 2010 study on X-linked cone dystrophy caused by cone opsin mutations tested the pharmacological chaperone 9-cis-retinal on the W177R misfolded protein in vitro and found it did not rescue the misfolding, unlike the effect of the same compound on a different opsin mutation that causes retinitis pigmentosa. No other drug, small molecule, or gene therapy was tested in any of the abstracts for this specific disease.

The 2016 Danish study argues that Åland eye disease, incomplete congenital stationary night blindness, and X-linked cone-rod dystrophy 3 are the same clinical entity, caused predominantly by mutations in CACNA1F. Among 60 affected males from 29 families, 59 had a CACNA1F mutation and 1 had a CABP4 mutation. Visual acuity was subnormal in all, nystagmus in 63%, and foveal hypoplasia in 25 of 43 subjects. Outer segment length at the fovea was significantly reduced compared to normal. The estimated birth prevalence was 1 per 22,000 live-born males. No treatment was tested or discussed.

The 1998 abstract describes adenovirus-mediated transfer of truncated dystrophin cDNAs into skeletal muscle of mdx mice, a model of Duchenne muscular dystrophy, not eye disease. The 1995 abstract describes the phenotype of a dominant cone-rod dystrophy linked to chromosome 19q, not X-linked. The 2024 case report describes a rod-cone dystrophy associated with a GNB1 mutation, a different gene and disease pattern.

What is missing for X-linked cone-rod dystrophy 3 is any clinical trial of a drug or gene therapy in patients. The only relevant experimental result is negative: 9-cis-retinal failed to rescue the misfolded cone opsin in cell culture. No animal model data, no safety data, no dosing information, and no patient stratification strategy exist in these abstracts for any therapeutic intervention.

Evidence

Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.

FEBS Letters · 1998 · 77 citations

Effective restoration of dystrophin‐associated proteins in vivo by adenovirus‐mediated transfer of truncated dystrophin cDNAs

AbstractA series of truncated dystrophin cDNAs (3.1-4.2 kbp) containing only three, three, two or one rod repeats with hinge 1 and 4 (named deltaDysAX2, AX11, AH3, M3, respectively) or no rod repeat retaining either hinge 1 or 4 (named deltaDysH1, H4, respectively) were constructed. These cDNAs were introduced into skeletal muscle of adult mdx mice using the adenovirus vector with a strong CAG promoter. deltaDysAX2, AX11, AH3 and deltaDysM3 expressed themselves successfully and recovered dystrophin-associated proteins effectively. Especially 3.7 kbp cDNA for deltaDysM3 offers the possibility of an approach utilizing newly developed virus vectors, such as an adeno-associated virus vector, toward gene therapy of Duchenne muscular dystrophy.

https://doi.org/10.1016/s0014-5793(98)00251-8
The American Journal of Human Genetics · 2010 · 58 citations · open access

X-Linked Cone Dystrophy Caused by Mutation of the Red and Green Cone Opsins

AbstractX-linked cone and cone-rod dystrophies (XLCOD and XLCORD) are a heterogeneous group of progressive disorders that solely or primarily affect cone photoreceptors. Mutations in exon ORF15 of the RPGR gene are the most common underlying cause. In a previous study, we excluded RPGR exon ORF15 in some families with XLCOD. Here, we report genetic mapping of XLCOD to Xq26.1-qter. A significant LOD score was detected with marker DXS8045 (Z(max) = 2.41 [theta = 0.0]). The disease locus encompasses the cone opsin gene array on Xq28. Analysis of the array revealed a missense mutation (c. 529T>C [p. W177R]) in exon 3 of both the long-wavelength-sensitive (LW, red) and medium-wavelength-sensitive (MW, green) cone opsin genes that segregated with disease. Both exon 3 sequences were identical and were derived from the MW gene as a result of gene conversion. The amino acid W177 is highly conserved in visual and nonvisual opsins across species. We show that W177R in MW opsin and the equivalent W161R mutation in rod opsin result in protein misfolding and retention in the endoplasmic reticulum. We also demonstrate that W177R misfolding, unlike the P23H mutation in rod opsin that causes retinitis pigmentosa, is not rescued by treatment with the pharmacological chaperone 9-cis-retinal. Mutations in the LW/MW cone opsin gene array can, therefore, lead to a spectrum of disease, ranging from color blindness to progressive cone dystrophy (XLCOD5).

https://doi.org/10.1016/j.ajhg.2010.05.019
Investigative Ophthalmology & Visual Science · 2016 · 32 citations · open access

Clinical Characteristics, Mutation Spectrum, and Prevalence of Åland Eye Disease/Incomplete Congenital Stationary Night Blindness in Denmark

AbstractPurpose: To assess clinical characteristics, foveal structure, mutation spectrum, and prevalence rate of Åland eye disease (AED)/incomplete congenital stationary night blindness (iCSNB). Methods: A retrospective survey included individuals diagnosed with AED at a national low-vision center from 1980 to 2014. A subset of affected males underwent ophthalmologic examinations including psychophysical tests, full-field electroretinography, and spectral-domain optical coherence tomography. Results: Over the 34-year period, 74 individuals from 35 families were diagnosed with AED. Sixty individuals from 29 families participated in a follow-up study of whom 59 harbored a CACNA1F mutation and 1 harbored a CABP4 mutation. Among the subjects with a CACNA1F mutation, subnormal visual acuity was present in all, nystagmus was present in 63%, and foveal hypoplasia was observed in 25/43 subjects. Foveal pit volume was significantly reduced as compared to normal (P < 0.0001). Additionally, outer segment length at the fovea was measured in 46 subjects and found to be significantly reduced as compared to normal (P < 0.001). Twenty-nine CACNA1F variations were detected among 34 families in the total cohort, and a novel CABP4 variation was identified in one family. The estimated mean birth prevalence rate was 1 per 22,000 live-born males. Conclusions: Our data support the viewpoint that AED, iCSNB, and X-linked cone-rod dystrophy 3 are designations that refer to a broad, continuous spectrum of clinical appearances caused in the majority by a variety of mutations in CACNA1F. We argue that the original designation AED should be used for this entity.

https://doi.org/10.1167/iovs.16-19445
Archives of Ophthalmology · 1995 · 29 citations

Chromosome 19q Cone-Rod Retinal Dystrophy

AbstractOBJECTIVE: To describe the phenotype in a family with dominantly inherited cone-rod dystrophy with chromosome assignment to a 19q locus, and to correlate this with current classifications of this retinal dystrophy. DESIGN: A detailed clinical examination including Goldmann perimetry was undertaken in all family members. Six members under the age of 30 years underwent dark-adapted electroretinography, color contrast-sensitivity measurement, dark-adapted static perimetry, and dark adaptometry. PATIENTS: The study included 34 affected and 22 unaffected patients in four generations of a pedigree that manifested autosomal dominant cone-rod retinal dystrophy linked to a chromosome 19q locus by genetic linkage analysis. RESULTS: Loss of visual acuity occurred in the first decade of life, onset of night blindness occurred after 20 years of age, and little visual function remained after the age of 50 years. Central and, later, peripheral retinal fundus changes were associated with central scotoma, pseudoaltitudinal field defects, and finally global loss of function. Psychophysical and electrophysiologic testing before the age of 26 years showed more marked loss of cone than rod function. CONCLUSIONS: The phenotype associated with this mutation does not fit well into previous subtypes of cone-rod dystrophy. Further studies will be needed to correlate specific genetic mutations in this group of conditions with the various clinical phenotypes.

https://doi.org/10.1001/archopht.1995.01100020079033
Case Reports in Ophthalmology · 2024 · 1 citations · open access

GNB1-Related Rod-Cone Dystrophy: A Case Report

Abstract&lt;b&gt;&lt;i&gt;Introduction:&lt;/i&gt;&lt;/b&gt; The &lt;i&gt;GNB1&lt;/i&gt; (guanine nucleotide-binding protein, β1) gene encodes for the ubiquitous β1 subunit of heterotrimeric G proteins, which are associated with G-protein-coupled receptors (GPCRs). &lt;i&gt;GNB1&lt;/i&gt; mutations cause a neurodevelopmental disorder characterized by a broad clinical spectrum. A novel variant has recently been confirmed in a case of rod-cone dystrophy. &lt;b&gt;&lt;i&gt;Case Presentation:&lt;/i&gt;&lt;/b&gt; We describe the second confirmed case of a classical rod-cone dystrophy associated with a mutation located in exon 6 of &lt;i&gt;GNB1&lt;/i&gt; [NM_002074.5:c.217G&amp;gt;C, p.(Ala73Pro)] in a 56-year-old patient also presenting mild intellectual disability, attention deficit/hyperactivity disorder, and truncal obesity. &lt;b&gt;&lt;i&gt;Conclusion:&lt;/i&gt;&lt;/b&gt; This paper confirms the role of &lt;i&gt;GNB1&lt;/i&gt; in the pathogenesis of a classic rod-cone dystrophy and highlights the importance of including this gene in the genetic analysis panel for inherited retinal diseases.

https://doi.org/10.1159/000537997

Disease module: DeepOracle (Open Targets). Structures: RDKit from PubChem SMILES. Literature: retrieved by DeepSearch across 234,678,978 indexed works (targeted per-candidate search), resolved on OpenAlex.

DeCure is a research and publication project, not medical advice and not a treatment. "DeCure for X" describes a research goal, not a claim that a cure exists. Backing a cure is a contribution to fund the research — it is not an investment, and confers no yield, royalty, equity or IP ownership. Papers are published open-access by the DeCure.ai DAO.