title: X-linked agammaglobulinemia caused by new mutation in BTK gene: a case report.
abstract: OBJECTIVE
  Primary immunodeficiencies (PID) are becoming a recognized public health problem worldwide. The most important subgroup of these disorders are the antibody deficiencies. X-linked agammaglobulinaemia was the first described entity of this group and is characterised by early onset of recurrent bacterial infections, profound deficiency of all immunoglobulin isotypes and markedly reduced number of peripheral B-lymphocytes.
  
  
  METHODS
  We report the case of a 10-year old boy with X-linked agammaglobulinaemia caused by a previously non-described mutation in BTK gene with typical clinical presentation but delayed diagnosis. Following diagnosis, substitution therapy with intravenous immunoglobulins was started and the clinical status of the patient improved.
  
  
  CONCLUSIONS
  We reported a case of X-linked agammaglobulinaemia with delayed diagnosis despite the typical anamnestic signs for primary humoral immunodeficiency. The disease was caused by a previously non-reported mutation in the BTK gene. Measurement of serum immunoglobulins should be performed in all children with recurrent, complicated respiratory infections as a screening test for humoral immunodeficiencies.
authors.affiliation: Department of Paediatrics, Centre for diagnosis and treatment of primary immunodeficiencies, Jessenius Faculty of Medicine, Commenius University in Bratislava, Martin, Slovakia.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Havlicekova
authors.forename: Milos
authors.initials: M
authors.lastname: Jesenak
authors.forename: Tomas
authors.initials: T
authors.lastname: Freiberger
authors.forename: Peter
authors.initials: P
authors.lastname: Banovcin
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D000361:Agammaglobulinemia / Q000188:drug therapy* / Q000235:genetics*; D002648:Child; D040181:Genetic Diseases, X-Linked / Q000188:drug therapy* / Q000235:genetics*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D008297:Male; D009154:Mutation; D011505:Protein-Tyrosine Kinases / Q000235:genetics*
chemical_list: D016756:Immunoglobulins, Intravenous; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human