Enhancement of a fra(16)(q22) with distamycin A: a family ascertained through an abnormal proposita.

A family in which a fragile site at 16q22 was segregating was ascertained through a newborn infant with multiple anomalies. The same fragile site was present in the phenotypically normal father and in a brother with cleft palate. The fra(16)(q22) was similar in appearance, and in response to culture conditions, to that reported by other investigators, including increased breakage in media supplemented with distamycin A. Sampling variation in the frequency of breakage over time may be considerable in some individuals. No pattern of anomalies was found to be associated with the fragile site. However, the reproductive history of the family we report (two livebirths with major congenital anomalies and one stillbirth) suggests caution in concluding fra(16)(q22) is not deleterious.