We report a new de novo case of a balanced whole-arm reciprocal translocation, detected at prenatal diagnosis for late maternal age. A review of previous cases indicates there is a risk of chromosomally abnormal liveborn offspring when a parent is a carrier of this type of translocation, particularly when the translocated region is a small chromosomal segment. Due to the limited number of cases, exact reproductive risks are not available. This is the second example of such a translocation of chromosomes 1 and 5, raising the possibility of nonrandom involvement of certain chromosomes in balanced nonacrocentric whole-arm reciprocal translocations.