IMPG2-related recessive retinopathy

Summary

IMPG2-related recessive retinopathy (MONDO:0700241) is a disease with 1 cohort gene.

At a glance

• Cohort genes: 1
• ClinVar variants: 1

Clinical features

No curated clinical features (Orphanet) for this disease.

Identifiers

Disease identifiers

Field	Value
Canonical name	IMPG2-related recessive retinopathy
Mondo ID	MONDO:0700241
GARD	0026390
Is cancer (heuristic)	no

Also known as: IMPG2-related recessive retinopathy

Data availability: 1 ClinVar variant.

Disease family

An umbrella term covering 1 Mondo subtype.

Classification path: disease › human disease › disease by body system or component › nervous system disorder › retinal disorder › retinal degeneration › inherited retinal dystrophy › IMPG2-related recessive retinopathy

Related subtypes (104): retinal dystrophies primarily involving Bruch’s membrane, vitreoretinal dystrophy, dystrophies primarily involving the retinal pigment epithelium, retinal dystrophy in systemic or cerebroretinal lipidoses, age-related macular degeneration, helicoid peripapillary chorioretinal degeneration, Sorsby fundus dystrophy, microcephaly with or without chorioretinopathy, lymphedema, or intellectual disability, pigmented paravenous retinochoroidal atrophy, retinoschisis, autosomal dominant, retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations, amaurosis-hypertrichosis syndrome, familial benign flecked retina, microcephaly and chorioretinopathy 1, ornithine aminotransferase deficiency, retinal degeneration-nanophthalmos-glaucoma syndrome, retinoschisis of fovea, Revesz syndrome, choroideremia, choroideremia-deafness-obesity syndrome, X-linked retinal dysplasia, X-linked retinoschisis, progressive bifocal chorioretinal atrophy, aceruloplasminemia, late-onset retinal degeneration, infantile cerebellar-retinal degeneration, progressive retinal dystrophy due to retinol transport defect, microcornea-myopic chorioretinal atrophy, retinal dystrophy with inner retinal dysfunction and ganglion cell anomalies, macular degeneration, early-onset, cone-rod dystrophy, ectopia lentis-chorioretinal dystrophy-myopia syndrome, foveal hypoplasia-presenile cataract syndrome, MRCS syndrome, X-linked intellectual disability-limb spasticity-retinal dystrophy-diabetes insipidus syndrome, Leber congenital amaurosis, oligocone trichromacy, Oguchi disease, retinitis pigmentosa, hereditary macular dystrophy, RPE65-related recessive retinopathy, RPGR-related retinopathy, AIPL1-related retinopathy, RP2-related retinopathy, RDH5-related retinopathy, RLBP1-related retinopathy, LCA5-related retinopathy, ATF6-related retinopathy, RAB28-related retinopathy, FLVCR1-related retinopathy with or without ataxia, RPE65-related dominant retinopathy, GUCY2D retinopathy, PDE6A-related retinopathy, ELOVL4-related maculopathy, MAK-related retinopathy, KIZ-related retinopathy, TOPORS-related retinopathy, PRPF8-related retinopathy, RD3-related retinopathy, BEST1-related dominant retinopathy, BEST1-related recessive retinopathy, IMPG2-related dominant retinopathy, CACNA1F-related retinopathy, CACNA2D4-related retinopathy, CDHR1-related retinopathy, GUCA1A-related retinopathy, RHO-related retinopathy, SNRNP200-related dominant retinopathy, RDH12-related recessive retinopathy, RDH12-related dominant retinopathy, NMNAT1-related retinopathy, CNGA3-related retinopathy, EYS-related retinopathy, GNAT2-related retinopathy, IDH3B-related retinopathy, MERTK-related retinopathy, PRPF31-related retinopathy, GPR179-related retinopathy, GRM6-related retinopathy, ADAM9-related retinopathy, RP1-related recessive retinopathy, RP1-related dominant retinopathy, CERKL-related retinopathy, TRPM1-related retinopathy, CNGB1-related retinopathy, PCARE-related retinopathy, CNGA1-related retinopathy, ABCA4-related retinopathy, NYX-related retinopathy, retinal dystrophy, X-linked, Gardner-Hardcastle type, PDE6C-related retinopathy, PDE6G-related retinopathy, LRIT3-related retinopathy, IMPG1-related dominant retinopathy, IMPG1-related recessive retinopathy, TTLL5-related retinopathy, HGSNAT-related retinopathy, IMPDH1-related retinopathy, PRPH2-related retinopathy, PROM1-related retinopathy, KCNV2-related retinopathy, CRX-related retinopathy, REEP6-related retinopathy, SPATA7-related retinopathy

Subtypes (1): retinitis pigmentosa 56

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

ClinVar germline variants

1 retrieved; paginated sample, class counts are floors:

1 pathogenic/likely pathogenic

ClinVar	Variant (HGVS)	Gene	Classification	Review
2017710	NM_016247.4(IMPG2):c.44del (p.Ile14_Leu15insTer)	IMPG2	Pathogenic/Likely pathogenic	criteria provided, multiple submitters, no conflicts

Genes & proteins

Mendelian disease overlap and somatic drivers

GenCC: 0 · Orphanet: 2 · OMIM-shared: 0 · Dual-evidence (GWAS+Mendelian): 0

Orphanet rare-disease linkage (cohort genes)

Gene	Orphanet ID	Rare disease
IMPG2	Orphanet:791	Retinitis pigmentosa
IMPG2	Orphanet:99000	Adult-onset foveomacular vitelliform dystrophy

Cohort genes → proteins

1 cohort genes, 1 distinct canonical proteins.

Evidence partition

Subset	Genes
multi_evidence	1

Cohort genes (full)

Symbol	HGNC	Ensembl	UniProt	Name	Evidence
IMPG2	HGNC:18362	ENSG00000081148	Q9BZV3	Interphotoreceptor matrix proteoglycan 2	clinvar

Cohort function summary

Lead sentence per gene, UniProt-curated.

Symbol	Protein name	Function (lead sentence)
IMPG2	Interphotoreceptor matrix proteoglycan 2	Chondroitin sulfate- and hyaluronan-binding proteoglycan involved in the organization of interphotoreceptor matrix; may participate in the maturation and maintenance of the light-sensitive photoreceptor outer segment.

Protein-family classification

Druggable: 0 · Difficult: 0 · Unknown: 1 · Druggable fraction: 0.0

Family distribution

Cohort families vs a genome-wide background (hypergeometric, BH-FDR; fold = observed/expected). Counts kept; sorted by enrichment, so the catch-all Other/Unknown bucket no longer leads.

Family	Genes	Fold	FDR
Other/Unknown	1	1.8×	0.558

Per-gene assignment

Symbol	Family	Druggable?	EC	InterPro (top 3)
IMPG2	Other/Unknown	no		SEA_dom, EGF, SEA_dom_sf

Expression context

Cohort genes with no expression data: 0.

1 cohort gene are a single-cell marker in ≥1 SCXA experiment.

Breadth distribution (Bgee present_calls)

Bucket	Genes
narrow (1-5 tissues)	0
moderate (6-20)	0
broad (>20)	1
unknown	0

Top tissues across cohort

Tissue	Cohort genes
male germ line stem cell (sensu Vertebrata) in testis	1
pineal body	1
right uterine tube	1

Per-gene tissue summary (top 30)

Symbol	Bgee breadth	FANTOM5 breadth	SCXA	Top tissues
IMPG2	81	tissue_specific	marker	right uterine tube, male germ line stem cell (sensu Vertebrata) in testis, pineal body

Protein interactions among cohort

Intra-cohort edges: 0.

Hub genes (top 10 by interactor count)

Symbol	Interactor count
IMPG2	516

Structural data

PDB: 0 · AlphaFold-only: 1 · No structure: 0

AlphaFold-only cohort genes (top 30 by pLDDT)

Symbol	UniProt	pLDDT
IMPG2	Q9BZV3	54.28

Function

Pathway analysis

Distinct Reactome pathways touched by cohort: 0. Enrichment computed across 1 evidence-associated genes (0 with Reactome annotation).

GO biological processes by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

GO term	Cohort genes	Fold	FDR	Sample cohort genes
retina morphogenesis in camera-type eye	1	1872.4×	0.002	IMPG2
extracellular matrix organization	1	122.1×	0.013	IMPG2
intracellular protein localization	1	104.7×	0.013	IMPG2
visual perception	1	79.5×	0.013	IMPG2

Therapeutics

Drug target analysis

Approved (phase 4): 0 · Phase ≥3: 0 · Phased (≥1): 0 · Undrugged: 1

Druggability breadth: 0 of 1 evidence-associated genes (0%) have a ChEMBL target (buckets above are over the deeply-mined display cohort).

Top cohort targets by molecule count

Symbol	Molecules	Max phase
IMPG2	0	0

Bioactivity and enzyme data

Enzyme cohort genes (≥1 EC): 0.

Pharmacogenomics

Cohort genes with a PharmGKB record: 1; with CPIC/DPWG dosing guidelines: 0.

No cohort gene has a CPIC/DPWG genotype-guided dosing guideline (PharmGKB).

Chemical tractability of cohort targets

0 approved/phased compounds have measured bioactivity against a cohort gene (and aren’t yet in disease-level trials). This is a research / tractability signal, NOT a therapeutic recommendation — a bioactivity row often reflects off-target or screening binding (e.g. promiscuous kinase inhibitors against a cohort kinase), implying no disease mechanism.

Druggability pyramid

Cohort genes binned by druggability tier (high → low):

Tier	Definition	Genes	Symbols
A	Approved (phase 4 drug)	0
B	Phased (≥1) drug, not yet approved	0
C	Druggable family + PDB, no drug	0
D	Druggable family + AlphaFold only, no drug	0
E	Difficult family or no structure, no drug	1	IMPG2

Undrugged target profiles

1 cohort genes are undrugged. Ranked by ‘starting-point quality’ (assay depth + drugged-partner adjacency).

Symbol	ChEMBL assays	Drugged partners (top 3)
IMPG2	0	—

Clinical trials & evidence

Clinical trials

Clinical trials: 0.