Paracentric inversion of Yq and review of the literature.

We report on the second prenatal diagnosis of familial paracentric inversion of the long arm of Y chromosome [46, X, inv(Y)(q11.2q12)]. The anomaly was detected through an amniocentesis performed because of advanced maternal age. The inversion has been detected by standard GTG banding methods and better characterized by FISH with painting probe and specific satellite probes DYZ1 and DYZ3. The inversion derived from phenotypically normal father. Pregnancy was uneventful and an healthy child was born. We discuss the issue concerning genetic prenatal counselling of this rare condition and we report the clinical follow up of the child.