SH3PXD2B and Axenfeld-Rieger syndrome: One (4.8%) of 21 primary congenital glaucoma subjects carried a Glu396Lys mutation that is located in the third SH3 domain and has a relatively benign blosum62 score of “1.” Two (6.7%) of the 30 Axenfeld-Rieger syndrome patients carried SH3PXD2B variations, one patient with Ala431Thr and another with Pro571Leu.