@article{b93ba5ae03a84345bc4d361f3fb94e74,
title = "Properdin deficiency associated with recurrent otitis media and pneumonia, and identification of male carrier with Klinefelter syndrome",
abstract = "Properdin is an initiator and stabilizer of the alternative complement activation pathway (AP). Deficiency of properdin is a rare X-linked condition characterized by increased susceptibility to infection with Neisseria meningitidis associated with a high mortality rate. We report properdin deficiency in a large Pakistani family. The index cases were found by screening for immunodeficiency due to a history of recurrent infections. This revealed absent AP activity, but normal classical and lectin pathway activity. Sequencing of the properdin gene (PFC) revealed a novel frameshift mutation. When all available relatives (n=24) were screened for the mutation, four affected males, four female carriers and a male heterozygous carrier were identified. He was subsequently diagnosed with Klinefelter syndrome. A questionnaire revealed a striking association between properdin deficiency and recurrent otitis media (P=0.0012), as well as recurrent pneumonia (P=0.0017). This study is the first to show a significant association between properdin deficiency and recurrent infections.",
keywords = "Female, Genetic Predisposition to Disease, Heterozygote, Humans, Klinefelter Syndrome, Male, Mutation, Otitis Media, Pedigree, Pneumonia, Properdin, Questionnaires, Recurrence, Retrospective Studies",
author = "Lone Schejbel and Vibeke Rosenfeldt and Hanne Marquart and Valerius, {Niels Henrik} and Peter Garred",
year = "2009",
doi = "10.1016/j.clim.2009.02.008",
language = "English",
volume = "131",
pages = "456--62",
journal = "Clinical immunology (Orlando, Fla.)",
issn = "1521-7035",
publisher = "Academic Press Inc.",
number = "3",
}