Although genetic studies have been limited due to the rarity of these patients, candidate gene approaches in juvenile AChR-Ab positive generalized patients with MG with the treatment-resistant ophthalmoplegic phenotype showed associations with regulatory variants in both the DAF (-198 C>G) and TGFB1 (-387 C>T) genes (74, 75). Here, TGFB1 is linked to myasthenia gravis.