Complemetation testing demonstrated allelism between this mutation and Adamts20bt-Bei1. Sequence analysis identified the molecular lesion as a a C-to-T transition at nucleotide position 2451 (NM_177431.5:c.2281C>T), which is predicted to replace a highly-conserved leucine in the protein's spacer domain with phenylalanine (L761F). (J:133403)