To the Editor.
—Dr Liu and colleagues1 recently reported the remarkably successful application of microsurgical techniques of epididymal sperm aspiration and intracytoplasmic sperm injection of stimulated oocytes. Following in vitro fertilization, blastomere biopsy was accomplished by micromanipulation. Analysis of DNA by polymerase chain reaction demonstrated the genotype of the embryos from two cystic fibrosis carriers.Five embryos were successfully fertilized. Two were homozygous for the ΔF508 genotype and three were carriers. These three carriers were transferred to the uterus and one successfully implanted. Subsequently, a phenotypically normal male infant was born.1 The article emphasized the preimplantation diagnosis of cystic fibrosis as well as the father's diagnosis of congenital bilateral absence of the vas deferens. The study, we are told, was approved by the institutional ethics committee. It is impossible to describe the joy that comes from the blessing of parenthood. We who are parents rejoice with this new