2026 American Academy of Neurology Abstract Website

Objective:

To describe a kinship with myotilinopathy where ptosis is identified as a prominent part of the phenotype, highlighting its significance in the diagnostic process.

Background:

Myotilinopathy is a slowly progressive myopathy characterized pathologically as a myofibrillar myopathy. It typically presents with leg muscle weakness, gait abnormalities, myalgia, muscle stiffness, and ankle joint contractures. This report details a kinship where eyelid ptosis emerges as a significant clinical feature, emphasizing the phenotypic variability within the same family.

Design/Methods:

Results:

The index patient, a 20-year-old man, presented with abnormal gait, toe-walking, hip swinging, and a wide-based gait from early childhood. Over time, he developed proximal muscle weakness, hand stiffness, and leg pain. Genetic testing confirmed a pathogenic MYOT c.170C>T variant. At age 13, he developed progressive bilateral non-fatigable ptosis, prompting tests for acetylcholine receptor binding and muscle-specific kinase antibody, both negative. An ophthalmology examination ruled out other causes of eyelid ptosis. Serum creatine kinase was mildly elevated at presentation. His cardiac and pulmonary functions are preserved.

The patient's paternal half-sister reported leg pain and left ptosis at age 13, with ankle flexion contractures mild left ptosis, and absent facial or limb muscle weakness on examination.

The patient’s biological father, diagnosed with presumed limb-girdle muscular dystrophy at 25, lost ambulation in his thirties and exhibited ptosis. His wife noted severe ptosis made him appear asleep while watching TV, despite being awake. He died at age 50 due to respiratory failure. Other family members, including the paternal grandmother, uncle, and two aunts, presented with myopathy but without ptosis.

Conclusions:

The presence of ptosis in this kinship underscores the phenotypic variability of myotilinopathy and highlights eyelid ptosis as a notable feature of the condition. Recognizing ptosis as part of the phenotype aids in streamlining diagnosis and avoiding unnecessary diagnostic procedures, thus enhancing patient care and management strategies.