Purpose: Prenatal diagnosis is offered to carriers of a balanced chromosomal rearrangement because it may predispose to offspring with an unbalanced karyotype. Therefore, carriers examined prenatally or in childhood should be informed before they reach reproductive age. We aimed to determine how many of the adult carriers ascertained in childhood currently know about their carrier status.
Methods: We used data obtained by a questionnaire study reexamining carriers of a balanced reciprocal translocation. When a carrier was older than 18 years of age and had been examined in childhood, relatives were asked whether she/he knew of the translocation.
Results: Among the 113 parents we interviewed, 10 carriers (9%) in 8 families had not been informed. In one of the eight families, an offspring with an unbalanced translocation was born 23 years after the father had been examined in childhood.
Conclusion: Because of our findings, the practice of genetic counseling in Denmark has been changed: When a carrier of a balanced chromosomal rearrangement who was examined prenatally or in childhood turns 18 years of age, the parents will receive a letter reminding the family about the reproductive risk.