Abstract
In 1991, we began a project to search for the genetic basis of asthma using linkage analysis. We encountered discord between a history of asthma and physiological measures of variable airflow obstruction and sought to examine the frequency of such occurrences and the issues surrounding phenotyping of patients with asthma. We reviewed our experience in ascertaining the asthma phenotype in 50 nuclear families comprised of 219 subjects (110 male, 109 female). Three respiratory physicians reviewed data including a questionnaire, skin testing, objective measures of variable airflow obstruction [increase in FEV1 > or = 15% following salbutamol 400 micrograms of PC20 (methacholine) < or = 4 mg/ml], and serum for IgE. Thirty-eight percent of subjects had both objective and questionnaire data consistent with asthma (++) whereas 39% had negative objective and negative questionnaire findings (--) (i.e., no asthma). A positive history but negative objective findings occurred in 7% of subjects, 2% had a negative history and positive objective findings. Retesting was requested in 13% of subjects; review of historical data was requested in 1% (i.e., childhood asthma but no present asthma). Retesting was requested for either (a) positive histo...Continue Reading
References
May 1, 1977·Clinical Allergy·D W CockcroftF E Hargreave
Feb 1, 1992·The Journal of Allergy and Clinical Immunology·P LympanyT H Lee
Feb 1, 1992·The American Review of Respiratory Disease·D P TashkinR Wise
Jul 1, 1991·Allergy·F PirsonD Vervloet
Jul 1, 1991·Chest·M M NieminenM Koskenvuo
Sep 1, 1990·The American Review of Respiratory Disease·P K PattemoreA W Stewart
Oct 1, 1990·The American Review of Respiratory Disease·E F JuniperF E Hargreave
Dec 1, 1990·The American Review of Respiratory Disease·D L DuffyJ D Mathews
Jun 10, 1989·Lancet·W O CooksonJ M Hopkin
Jan 1, 1985·Journal of Periodontal Research·W J PerosZ Skobe
Aug 1, 1988·Chest·P A EgglestonM F Alexander
Aug 1, 1971·Acta Allergologica·M L Edfors-Lubs
Jul 1, 1984·Thorax·E F JuniperF E Hargreave
May 1, 1980·Clinical Allergy·B Sibbald
Nov 1, 1994·American Journal of Respiratory and Critical Care Medicine·D A Meyers
Jan 1, 1994·American Journal of Respiratory and Critical Care Medicine·J S BignonD Charron
Apr 1, 1994·Chest·L P BouletA Brochu
Jul 1, 1993·The Journal of Allergy and Clinical Immunology·P A LympanyT H Lee
Jan 1, 1993·The American Review of Respiratory Disease·D P TashkinA H Coulson