Formoterol dry powder in asthma.

We read with interest the paper by Douglas and coworkers (July 1993;48,719-21) on the possible inheritance of sleep disturbed breathing. Investigating 40 first degree relatives of patients with sleep apnoeas, they found a high prevalence of sleep apnoeas/ hypopnoeas (25%), several times higher than the prevalence in a random sample of the British population (5%).' The authors concluded that a familial predisposition to sleep apnoeas/hypopnoeas is probable. If such a predisposition is inheritable, so must be the first stage of the syndrome that is, habitual snoring.2 To test this hypothesis we analysed the results of a questionnaire