Carboxypeptidase N is a serum alpha globulin metalloenzyme that inactivates C3a, C4a, C5a, bradykinin, kallidin, and fibrinopeptides. Mathews et al. (1980) found a low level of this enzyme (21% of normal) in a 65-year-old man with an 11-year ... Carboxypeptidase N is a serum alpha globulin metalloenzyme that inactivates C3a, C4a, C5a, bradykinin, kallidin, and fibrinopeptides. Mathews et al. (1980) found a low level of this enzyme (21% of normal) in a 65-year-old man with an 11-year history of episodic angioedema occurring about 40 times a year. The attacks, which lasted about 24 hours, most often involved the face and tongue but sometimes involved larger areas of pruritic, red swellings on the trunk or limbs. His sister had an equally depressed level of enzyme activity. Six children of these 2 sibs had intermediate levels consistent with heterozygous status. Multiple members of the family had allergic manifestations, i.e., angioedema/chronic urticaria, hay fever/asthma, or both.
By sequencing the CPN1 gene in genomic DNA extracted from cells of the index patient reported by Mathews et al. (1980), Cao and Hegele (2003) demonstrated that the allergic manifestations in this family were due to presumed compound ... By sequencing the CPN1 gene in genomic DNA extracted from cells of the index patient reported by Mathews et al. (1980), Cao and Hegele (2003) demonstrated that the allergic manifestations in this family were due to presumed compound heterozygosity for 2 mutations in the CPN1 gene (see 603103.0001 and 603103.0002).