Prenatal diagnosis of a de novo non-fluorescent Y chromosome.

We report a case with non-mosaic Yq-, missing the fluorescent segment, and detected as a fetus studied for advanced maternal age. The father had a Y chromosome of average size and paternity was established wih a plausibility of 97.7% by HLA and erythrocyte antigen typing. The child had a normal male antigen typing. The child had a normal male phenotype at delivery and developmental milestones were normal through the first year of life. The Yq- showed no mitotic instability since it was retained in foreskin culture for its in vitro lifetime of 60 population doublings.