Identification and characterization of normal length nonfluorescent Y chromosomes: cytogenetic analysis, southern hybridization and non-isotopic in situ hybridization.

In two female patients with a 45,X/46,X, +mar karyotype the marker chromosomes were identified as normal length nonfluorescent Y chromosomes (nlYnf) using non-isotopic in situ hybridization (NISH) complementary to routine cytogenetic analysis and Southern hybridization. The recognition of the nlYnf as isodicentric in both patients illustrates and confirms the usefulness and importance of NISH in the identification and characterization of this and many other types of complex chromosome rearrangements.