BACKGROUND: Cases of angioedema with no family history but with functionally low levels of C1 inhibitor and recurrent attacks are often observed. Clinical and biochemical data do not distinguish these cases from proven inherited forms of hereditary angioedema. OBJECTIVE: We sought to test the hypothesis of de novo mutations in patients affected by angioedema without a family history of the disease. METHODS: Among 137 independent kindreds followed for hereditary angioedema, 45 (32.8%) patients with early onset of the disease were registered as sporadic cases. Nineteen patients with unaffected parents were screened for point mutations and microdeletions-insertions by using fluorescence-assisted mismatch analysis. The biologic paternity of these patients was verified by determining their alleles at 4 microsatellite loci. Gross deletions were detected with Southern blot analysis. RESULTS: C1 inhibitor plasma levels measured in both parents of 24 sporadic patients were normal in all but 3 patients. Among the 19 patients studied at the DNA level, 9 de novo single nucleotide substitutions and 6 de novo microdeletions were found. De novo exon deletions were detected in 3 additional patients with Southern blot analysis. CONCLUSIONS: De novo C1inhibitor mutations and exon deletions account for at least 25% of all unrelated cases of angioedema. This finding has implications relevant to the genetic epidemiology and genetic counseling of this disease. The observation that 5 of the 9 de novo point mutations reproduce previously reported changes underlines the presence of multiple hot spots, two of which contain a CpG dinucleotide.
BACKGROUND: Cases of angioedema with no family history but with functionally low levels of C1 inhibitor and recurrent attacks are often observed. Clinical and biochemical data do not distinguish these cases from proven inherited forms of hereditary angioedema. OBJECTIVE: We sought to test the hypothesis of de novo mutations in patients affected by angioedema without a family history of the disease. METHODS: Among 137 independent kindreds followed for hereditary angioedema, 45 (32.8%) patients with early onset of the disease were registered as sporadic cases. Nineteen patients with unaffected parents were screened for point mutations and microdeletions-insertions by using fluorescence-assisted mismatch analysis. The biologic paternity of these patients was verified by determining their alleles at 4 microsatellite loci. Gross deletions were detected with Southern blot analysis. RESULTS: C1 inhibitor plasma levels measured in both parents of 24 sporadic patients were normal in all but 3 patients. Among the 19 patients studied at the DNA level, 9 de novo single nucleotide substitutions and 6 de novo microdeletions were found. De novo exon deletions were detected in 3 additional patients with Southern blot analysis. CONCLUSIONS: De novo C1inhibitor mutations and exon deletions account for at least 25% of all unrelated cases of angioedema. This finding has implications relevant to the genetic epidemiology and genetic counseling of this disease. The observation that 5 of the 9 de novo point mutations reproduce previously reported changes underlines the presence of multiple hot spots, two of which contain a CpG dinucleotide.
Authors: Angelo Agostoni; Emel Aygören-Pürsün; Karen E Binkley; Alvaro Blanch; Konrad Bork; Laurence Bouillet; Christoph Bucher; Anthony J Castaldo; Marco Cicardi; Alvin E Davis; Caterina De Carolis; Christian Drouet; Christiane Duponchel; Henriette Farkas; Kálmán Fáy; Béla Fekete; Bettina Fischer; Luigi Fontana; George Füst; Roberto Giacomelli; Albrecht Gröner; C Erik Hack; George Harmat; John Jakenfelds; Mathias Juers; Lajos Kalmár; Pál N Kaposi; István Karádi; Arianna Kitzinger; Tímea Kollár; Wolfhart Kreuz; Peter Lakatos; Hilary J Longhurst; Margarita Lopez-Trascasa; Inmaculada Martinez-Saguer; Nicole Monnier; István Nagy; Eva Németh; Erik Waage Nielsen; Jan H Nuijens; Caroline O'grady; Emanuela Pappalardo; Vincenzo Penna; Carlo Perricone; Roberto Perricone; Ursula Rauch; Olga Roche; Eva Rusicke; Peter J Späth; George Szendei; Edit Takács; Attila Tordai; Lennart Truedsson; Lilian Varga; Beáta Visy; Kayla Williams; Andrea Zanichelli; Lorenza Zingale Journal: J Allergy Clin Immunol Date: 2004-09 Impact factor: 10.793
Authors: Didier G Ebo; Marjoke M Verweij; Kathleen J De Knop; Margo M Hagendorens; Chris H Bridts; Luc S De Clerck; Wim J Stevens Journal: Paediatr Drugs Date: 2010-08-01 Impact factor: 3.022