From expression pattern to genetic association in asthma and asthma-related phenotypes

BMC Research Notes

Table 2 Clinical characteristics of the French-Canadian family study

	Probands^a	Family members
	n = 253	n = 1031
Male: Female ratio	1 : 1.1	1 : 1.2
Mean age, yr (range)	18 (3–50)	44 (2–93)
Smoking status, n (%)
Never	211 (85)	473 (47)
Ex-smoker	12 (5)	342 (34)
Smoker	25 (10)	197 (19)
FEV₁, % predicted (SD) ^b	92.7 (15.7)	94.6 (20.3)
PC₂₀, mg/ml (SD) ^c	2.53 (3.51)	10.06 (4.97)
Serum IgE in μg/l (SD) ^d	254.2 (4.9)	112.4 (4.4)
Number of persons with subphenotypes (%)
Asthma ^e	253 (100)	378 (37)
Atopy ^f	200 (79)	509 (49)
Atopic asthma (Asthma + Atopy)	200 (79)	257 (25)

^a Probands are first affected family member recruited in the familial collection and family members refers to other family members who joined the study.
^b FEV₁ = Mean calculated for the forced expiratory volume in one second evaluated for 217 probands and 770 family members.
^c PC₂₀ = Provocative concentration of methacholine that induces a 20% fall in FEV₁. Geometric mean and SD evaluated for 192 probands and 711 family members.
^d IgE = Immunoglobulin E serum concentration. Geometric mean and SD evaluated for 237 probands and 820 family members.
^e Present asthma or past documented clinical history of asthma. The reported mean age of onset is 7 years among the probands and 22 years among the asthmatic family members. Asthma phenotype was evaluated for 1022 subjects.
^f Defined as at least one positive response on skin prick test (wheal diameter > 3 mm at 10 minutes). Atopy phenotype was evaluated for 997 subjects.

ISSN: 1756-0500