We were very interested in the letter1 from Dr. Harrison1 in which she commented both on the high incidence of genitourinary infections families in which there was a high incidence of allergic problems, and also on the frequency with which genitourinary and allergic problems appeared to be concentrated in families. She asked if there was any explanation. We think there is. We ourselves have recently studied a group of 89 girls with recurrent urinary infections, and expect soon to publish our results.