Some of the most recently identified distal myopathy genes elucidate this diagnostic challenge at hand: some of them lack an obvious functional connection to muscle tissue (e.g. RILPL1), have previously been associated with an unrelated clinical phenotype (e.g. SMPX) or harbor highly elusive variants (e.g. HNRNPA1), and thus, are extremely difficult to identify. The gene discussed is SMPX; the disease is distal myopathy.