OPDM TBC1D7

This is a newly proposed locus for OPDM, only havng been reported in one paper¹. Oculopharyngodistal myopathy (OPDM) is a rare, adult-onset hereditary muscle disease. People with OPDM present with progressive eye and throat (pharyngeal) problems and involvement of the muscles of the lower legs and arms. Symptoms may include eyelid drooping (ptosis), swallowing difficulty, hoarse and nasal voice, leg and arm weakness, as well as muscle wasting in the face and in the legs and arms. Many people have respiratory problems due to respiratory muscle weakness. In rare cases, there is also hearing loss, as well as severe weakness in muscles of the forearms and thighs. As the disease progresses, other muscles may be affected. A blood exam may show an increased creatine kinase level and an abnormal EMG².

Prevalence

Found in 3 families (7 total patients) of European ancestry¹.

Age of Onset Details

2nd to 6th decade (3/5 patients had onset in 2nd decade). Referred to as adult onset, so assuming high end of 2nd decade.¹

Locus

hg19

chr6:13328708-13328835

hg38

chr6:13328476-13328603

t2t

chr6:13201716-13201843

Details

Benign range (0-60) estimated from population data and pathogenic range (83-148) gathered from 7 patients from 3 unrelated families¹. The hg38 coordinates reported in the paper (chr6:13328476-13328603)¹contain multiple annotated TRs an interruptions, so the true coordinates are likely more narrow.

Mechanism

GoF

Gain of Function apparent, but mechanism is unknown. Methylation and RAN translation have been oberseved¹.

Year

2026¹

Location in Gene

5' UTR

Gene Strand

Alleles

Ref. Motif

GCC

Pathogenic (ref.)

GCC

Pathogenic (gene)

CGG

References

Direct supporting references for info on this page.

A 5' UTR CCG expansion in

Liedewei,Van de Vondel, Riccardo,Curro, Stefano,Facchini, Isaac R L,Xu, Jonathan,De Winter, Ilaria,Quartesan, Alice,Monticelli, Alicia,Alonso-Jimenez, Willem,De Ridder, Alessandro,Bertini, Gustavo,Alves, Francesca,Pizzuto, Hermione,Ugolini, David,Pellerin, Tim,De Pooter, Ashirwad,Merve, Pedro,Machado, Lydia,Sagath, Kornelia,Neveling, Alexander,Hoischen, Michael G,Hanna, Robert D S,Pitceathly, Henry,Houlden, Arianna,Tucci, Enrico,Bugiardini, Stefen,Brady, Mark,Roberts, Matt C,Danzi, Stephan,Züchner, Jonathan,Baets, Andrea,Cortese

medRxiv : the preprint server for health sciences · 2026-04-01

pmid:41959811

Ontology Lookup Service (OLS)

mondo:0025193