[Familial chronic progressive blepharoptosis without other neurological symptoms: a new clinical entity?].

Nine patients over 5 generations developed progressive bilateral blepharoptosis from 40 to 50 years of age, suggesting that they had an autosomal dominantly inherited blepharoptosis. Except for the ptosis, they had no apparent neurological symptoms: normal ocular movement, no bulbar sign and no muscle weakness in the extremities. On laboratory examination, serum creatine kinase and blood lactate levels were within normal limits, and acetylcholine receptor antibody was not elevated. Electrophysiological studies including EMG and nerve conduction velocities were normal. Muscle biopsies from gastrocnemius and palpebral muscles were nondiagnostic with no ragged-red fibers nor rimmed vacuoles. Nuclear inclusions were not recognized by electron microscopy. Since none of patients examined had mitochondrial DNA deletions and GCG repeat expansion in the poly A binding protein P2 (PABP2) gene, this familial disorder is a unique blepharoptosis with no relationship to progressive external ophthalmoplegia or oculopharyngeal muscular dystrophy with PABP2 mutation.