FAT4 and myasthenia gravis: While the top ten mutated genes in the high MG score groups were TTN, TP53, MUC16, LRP1B, SYNE1, ARID1A, FLG, CSMD3, FAT4 and PCLO. Patients with low MG scores had markedly higher frequencies of TTN, MUC16, and ARID1A mutations than those with high MG scores.