A novel mutation W388X underlying properdin deficiency in a Finnish family.

Properdin deficiency is a rare immunological disorder inherited as an X-chromosomal recessive trait. Properdin deficiency poses a significant risk for severe meningococcal infections. About 20 mutations have been reported to underlie properdin deficiency. Here we report a large Finnish family with a novel mutation in the properdin gene (CFP). Based on the total absence of properdin activity in a 14-year-old male patient with an infection resembling meningococcal bacteraemia, the coding region and splice sites of the gene were sequenced. The mutation is located in exon 9 and changes guanine to adenine at nucleotide 1164 (c.1164G>A) that causes tryptophan to change to a premature stop codon (W388X). The mother of the patient was shown to be a carrier of the mutation. In total, the mutation was identified in six females and three young males in the family. The mutation must be inherited from the grandfather who had died of an unknown infectious disease. This is the first mutation of the properdin gene identified in Finland.