OPMD_PABPN1

Gene
PABPN1
Disease
OPMD
Inheritance
AD/AR
Classification
Definitive
Total Score
15
Publications Reviewed
5
Publication Span
24.58 years
Last Updated
08/14/2025
Curator(s)
Macayla Weiner, Laurel Hiatt

Description

Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset myopathy characterized by ptosis, dysphagia, and proximal limb weakness. The curated locus is the short GCN/GCG repeat in exon 1 of PABPN1 (formerly PABP2), where expansions enlarge the N-terminal polyalanine tract and are associated with autosomal dominant and recessive OPMD. Uploaded genetic evidence supports pathogenic repeat expansions through large clinically characterized cohorts, founder/segregation haplotype data, and genotype–phenotype correlations including expansion-size and gene-dose effects.

Genetic evidence

Total: 12

Singular EvidenceProbandsPMID:351127616Canary Islands cohort of 123 genetically diagnosed OPMD patients; 113/120 analyzed patients (94.2%) carried a heterozygous PABPN1 (GCN)15 expanded allele, with typical OPMD features including ptosis, dysphagia, and later proximal weakness.
Collective EvidenceAllelePMID:28011929 PMID:93920202PMID 28011929: French cohort of 354 unrelated index cases showed pathogenic PABPN1 (GCN)11–17 alleles and a correlation between expansion size and age at diagnosis/severity, with homozygous patients more severely affected. PMID 9392020: linkage study supports the chromosome 14 OPMD locus but is gene/locus-mapping evidence, not repeat allele size-specific.
Collective EvidenceSegregationPMID:110877661.5In 23 Bukhara Jewish patients from 8 unrelated families, all carried the PABP2/PABPN1 (GCG)9 mutation and shared a four-marker haplotype, supporting segregation of a shared founder mutation in this population.
StatisticsCase-control dataPMID:280119296French diagnostic cohort of 354 unrelated PABPN1 expansion-positive index cases characterized pathogenic (GCN)11–17 alleles; 200 control chromosomes had no (GCN)11 allele, supporting enrichment/rarity of expanded alleles in affected individuals versus controls.
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Experimental evidence

Total: 3

FunctionBiochemical functionPMID:94627470.5Gene-level, not repeat-locus-specific: PABP2/PABPN1 is a nuclear poly(A)-binding protein involved in mRNA polyadenylation; the paper proposed that expanded polyalanine PABP2 may accumulate as nuclear filament inclusions.
FunctionProtein interactionPMID:94627470.5
FunctionRegulatory impactPMID:94627470.5
Functional AlterationPatient cellsPMID:94627471
Functional AlterationNon-patient cellsPMID:94627470.5
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Note: Maximum score caps apply at evidence type, category, and supercategory levels, so section totals may be lower than the raw sum of row scores.