Oculopharyngeal Muscular Dystrophy

Clinical Characteristics
Ocular Features: 

Progressive ptosis is the cardinal ocular feature of this syndrome (present in at least 88% of patients).  External ophthalmoparesis of some degree is often present with weakness of upgaze most common.

Systemic Features: 

This is a late onset form of progressive muscular dystrophy with onset of symptoms during midlife (mean age of onset ~48 years).  Evidence of pharyngeal muscle weakness often occurs concomitantly with the ocular signs (43%).  Ptosis occurs first in 43% and dysphagia first in 14%.    Dysarthria and dysphagia are often associated with facial muscle weakness.  Swallowing times for ice cold water and dry food is usually prolonged.  Evidence of weakness and wasting of neck and limb muscles is usually noted later.  Life expectancy is normal in contrast to some other forms of muscular dystrophy.  Some patients have significant gait problems and generalized disability as a result of muscle weakness.

Microscopic studies of muscle biopsies usually show evidence of myopathy with abnormal fibers and accumulations of sarcoplasmic matter.  Intranuclear inclusions consisting of tubular filaments and mitochondrial abnormalities have also been described.  Serum CK can be significantly elevated in severe cases.  

Genetics

This is an autosomal dominant disorder resulting from mutations in the PABPN1 gene located at 14q11.2-q13. Several patients with homozygous and compound heterozygous mutations have also been reported.  The PABPN1 gene product is normally a facilitator of polyadenylation of mRNA molecules and may also be active in regulating mRNA production.

Treatment
Treatment Options: 

Blepharoplasty may be helpful in cases with severe ptosis.  Cricopharyngeal myotomy for dysphagia and recurrent pneumonia can alleviate symptoms in severe cases although recurrence has been noted after many years.

References
Article Title: 

References

van der Sluijs BM, Lassche S, Knuiman GJ, Kusters B, Heerschap A, Hopman M, Schreuder TH, van Engelen BGM, Voermans NC. Involvement of pelvic girdle and proximal leg muscles in early oculopharyngeal muscular dystrophy. Neuromuscul Disord. 2017 Sep 28. pii: S0960-8966(17)30473-X. doi: 10.1016/j.nmd.2017.09.010. [Epub ahead of print].

PubMedID: 29102430

Witting N, Mensah A, K??ber L, Bundgaard H, Petri H, Duno M, Milea D, Vissing J. Ocular, bulbar, limb, and cardiopulmonary involvement in oculopharyngeal muscular dystrophy. Acta Neurol Scand. 2014 Mar 10. Epub ahead of print].

PubMedID: 24611576

Becher MW, Morrison L, Davis LE, Maki WC, King MK, Bicknell JM, Reinert BL, Bartolo C, Bear DG. Oculopharyngeal muscular dystrophy in Hispanic New Mexicans. JAMA. 2001 Nov 21;286(19):2437-40.

PubMedID: 11712939

VICTOR M, HAYES R, ADAMS RD. Oculopharyngeal muscular dystrophy. A familial disease of late life characterized by dysphagia and progressive ptosis of the evelids. N Engl J Med. 1962 Dec 20;267:1267-72.

PubMedID: 13997067