A HITHERTO UNKNOWN SPLICE-SITE DEFECT IN THE PROTEIN-S GENE (PROS1) -THE MUTATION RESULTS IN ALLELIC EXCLUSION AND CAUSES TYPE-I AND TYPE-III PROTEIN-S DEFICIENCY

A hitherto unknown splice site mutation, in the splice acceptor of int ron B (tctag to tctgg), was identified in a symptomatic patient with t ype III protein S deficiency. The mutation co-segregated with type I/I II protein S deficiency in the patient's family, RNA analysis showed a llelic exclusion of the mutant transcript in affected individuals, The apparent type III deficiency in the propositus was not associated wit h the protein S Heerlen variant.