Partial trisomy 21: a fifty-year follow-up visit.

We describe a clinical encounter with family members that carry a balanced translocation involving chromosomes 15 and 21 roughly 50 years after the proband was diagnosed with partial trisomy 21 due to an unbalanced translocation. We discuss how these chromosomal rearrangements have impacted the lives of these individuals, and how they responded to revisiting their diagnoses after using updated cytogenetic techniques including high resolution chromosome banding and array comparative genomic hybridization.