Complex chromosome re‐arrangement 45,X,t(Y;9) in a girl with sex reversal and mental retardation

A girl with mental retardation and multiple minor anomalies was found to have a complex chromosome 9p re‐arrangement comprising a deleted, translocated Y chromosome, a deletion of the sex reversal gene region ( DMRT1 ) at 9p, together with an inverted duplication of the more proximal part of 9p. The karyotype was 45,X,der(Y;9)(Ypter→Yq12::9p21.1→9p22.2::9p22.2→9qter) de novo. The karyotypic male, phenotypic female had a dysgerminoma of the left dysplastic ovary. The patient had typical ‘trisomy 9p’ syndrome, and we propose that the critical region for this phenotype is located between 9p22.1 and 9p22.2. © 2003 Wiley‐Liss, Inc.