Background:

this is the first time in the world that the variant NM_000152 (GAA_V001):c.1555A˃G; p.(Met519Val), is a described in an adult woman, triggered by pregnancy. It is a substitution for a non-sense, homozygous, probably pathogenic mutation.

Case report:

this is the case of a mestizo adult woman, born and resident in Ecuador, who during her breastfeeding period, after a pregnancy and cesarean delivery, it did debut with a musculoskeletal disorder. It hospitalized this patient at the Eugenio Espejo Hospital in Quito Ecuador; she has been re-admitted several times. Most relevant clinical findings were proximal muscle weakness, lower limb muscle weakness, difficulty in climbing stairs, respiratory insufficiency due to muscle weakness, edema of her lower limbs, impairment of activities of daily living, orthopnea, sleep disturbance, muscle weakness, elevated serum creatine kinase, abnormal enzyme/coenzyme activity, lumbar scoliosis, pulmonary arterial hypertension, with tricuspid regurgitation and mild mitral regurgitation, fatty replacement of skeletal muscle, pulmonary insufficiency, skeletal myopathy and myotonic discharges in EMG.

Conclusion:

this is the first time worldwide that the variant NM_000152(GAA_V001):c.1555A˃G; p.(Met519Val), a substitution by a missense mutation, homozygous, likely pathogenic is describe in an adult. It is the first case triggered by pregnancy , first case of late onset described in Ecuador, and first case described in a mestizo woman from Ecuador.