In geriatric MM patients, the most frequently observed variants were BRAF V600E (14.55%) and V600K (7.27%) in Exon 15, followed by NRAS (10.90%), NF1 (9.09%), KIT and KRAS (5.45% each), CDKN2A (3.64%), and PTEN (3.63%). The gene discussed is PTEN; the disease is Miyoshi myopathy.