Limb girdle muscular dystrophies, myofibrillar myopathies and distal myopathies

STR: PABPN1_GCN

Green List (high evidence)

PMID: 27858728 Richard et al., 2015
Case report of a male patients with disease onset at age 60 years - slowly progressive OPMD. He presented with dysphagia, mild ptosis (at 83 years), lower limb weakness. CT scan of lower limbs showed a hypodense aspect of glutei, posterior thigh and leg compartment muscles. CK slightly elevated. Muscle biopsy showed PABPN1 intranuclear inclusions. Classical Ala11 (GCN)11 expansion in PABPN1 detected. Dominant (though milder) disease despite harbouring the Ala11 "recessive" allele.

PMID: 28011929 Richard et al., 2017
French cohort of 354 unrelated index cases with Oculopharyngeal muscular dystrophy (OPMD) - an autosomal dominant adult-onset disease characterized by progressive ptosis, dysphagia, and proximal limb weakness. Key findings:
1. Patients with longer expansions have earlier disease onset (range of 11-17, 10 = WT). Earliest onset around age 30-40 years, late onset in 60s-70s.
2. Patients with biallelic variants present with more severe disease.
3. Reported 6 cases with heterozygous Ala11 allele, confirming that Ala11 can also act as a dominant mutation with low penetrance.

PABPN1 is linked to AD Oculopharyngeal muscular dystrophy, OMIM:164300 (OMIM accessed 16 Mar 2026).
Sources: Literature

Created: 16 Mar 2026, 5:31 p.m. | Last Modified: 16 Mar 2026, 5:50 p.m.

Panel Version: 5.39

Mode of inheritance
BOTH monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal

Phenotypes
Oculopharyngeal muscular dystrophy, OMIM:164300; oculopharyngeal muscular dystrophy, MONDO:0008116

Publications

• 27858728
• 28011929