The process for this is: 1) perform nerve conduction studies to differentiate between axonal and demyelinating patterns; 2) detect the presence of anti-MAG antibodies (anti-myelin-associated glycoprotein); 3) order serum-free light chain concentration and ratio; 4) screen for red flag features such as dysautonomia, weight loss, cutaneous signs, and heart, kidney, or lung involvement to rule out cryoglobulinemia or amyloidosis; 5) confirm the diagnosis with GQ1b, GT1B, or GD1b antibodies [1]. The gene discussed is MAG; the disease is cryoglobulinemia.