The most common POAG mutations reside within myocilin (MYOC), which is a gene located on chromosome 1 (GLC1A) that encodes the protein myocilin, including N450Y, Y437H, G364V, Q368X, K423E, I477N, and P370L.55,56 Studies have revealed that the MYOC mutation causes about 4% of POAG cases, of which the most common type is juvenile open-angle glaucoma. The gene discussed is MYOC; the disease is juvenile open angle glaucoma.