Introduction: Limb girdle myasthenia (LGM) is rare variant of myasthenia and differs from common forms in terms of presentation and distribution of weakness.

Presentation: Child1: 8 year-old previously healthy boy presented with severe abdominal pain aggravated on attempting to sit, stand/walk since 10 days without diurnal variation; difficulty in walking, getting up from floor since 4 days. Examination revealed hip girdle, truncal and neck flexor weakness and Gowers’ sign. No facial, bulbar/extra-ocular weakness. Sinuous gait was noted when he started walking.

Child2: 11 year, developmentally normal boy presented with severe pain in lower limbs and abdomen, difficulty in sitting, standing/walking since 15 days. He had 4-5 such episodes in past 2 years, improved spontaneously over 7-10 days with asymptomatic period of 3-4 months. Examination-similar to child1.

Management: Electrolytes, Thyroid profile, CPK, Urine-Porphobillinogen, ANA, Anti-AchR and Anti-Musk antibodies, CT chest were normal. NCS: Normal. Repetitive Nerve Stimulation Test: 60% & 90% decrement in nasalis, trapezius in child 1 and 2 respectively. Both showed dramatic improvement following IV Neostigmine, and continued on oral pyridostigmin.

Discussion: LGM is rare form of MG with prominent proximal muscle weakness, little/no ocular, bulbar or facial weakness. Most autoimmune LGM present after third decade and associated with thymoma. Episodic long-term fluctuations (precipitated by febrile illnesses) and absent diurnal fluctuations is characteristic. Cholinesterase inhibitors (pyridostigmine), corticosteroids (in acquired cases) are mainstay of therapy, with some cases requiring IV steroids, IVIG and/or immunomodulation.

Conclusion: LGM is rare treatable neuromuscular disorder. High index of suspicion helps in early diagnosis.