Table 2 Clinical characteristics of UK families

Age (mean years), ±SD

26.2 ± 1.6

13.3 ± 4.4

10.3 ± 4.6

Gender (% female)

50.8

54.6

53.7

Asthma (%, doctor diagnosed)

61.6

100

100

FEV₁ (% predicted, ±SD)

ND

95.4 ± 15.6

96.2 ± 14.9

Positive skin prick test (%)

62.5

73.9

65.1

Log total serum IgE (mean ± SD)

2.04 ± 0.7

2.33 ± 0.7

2.33 ± 0.7

Eczema (%, questionnaire)

41.1

53.5

55.1

Hay fever (%, questionnaire)

50.2

64.9

47.4

BTS (%) step 1

19.1

24.9

23.8

• Step 2

32.5

52.7

55.7

• Step 3

6.1

11.6

10.2

• Step 4

1.8

4.6

1.4

• Step 5

2.9

4.6

5.3

PC₂₀ (4 mg/ml,%)

46.9

59.9

n

1578

370

361