While congenital hypertrophic pyloric stenosis occurs quite regularly and not at all infrequently, it apparently afflicts more than one member of a family very rarely and familial occurrences of this kind are distinctly sporadic. In this country there are now approximately 4,000,000 live births annually; so, at the rate of 3 pyloric stenosis cases per 1,000, about 12,000 infants are found to have the disease every year. But, according to case reports, American clinicians do not observe its familial occurrence once a year. In fact, as we shall see, there are recorded in the world literature for all time fewer than 125 authentic cases, and if all reports which have been published were counted, irrespective of their validity, the number would still be extremely small.
For this reason alone, then, all familial occurrences should be reported, but for another and perhaps better one they merit publication, and that is to