Molecular‑cytogenetic study of de novo mosaic karyotype 45,X/46,X,i(Yq)/46,X,idic(Yq) in an azoospermic male: Case report and literature review

The present study describes a 36-year-old male with the 45,X/46,X,i(Yq)/46,X,idic(Yq) karyotype, who suffered from azoospermia attributed to maturation arrest of the primary spermatocyte. To the best of our knowledge, this rare karyotype has not yet been reported in the literature. The results of detailed molecular-cytogenetic studies of isodicentric (idic) Y chromosomes and isochromosome (iso) Y, which are identified in patient with complex mosaic karyotypes, are presented. The presence of mosaicism of the three cell lines 45,X, 46,X,i(Yq) and 46,X, idic(Yq) may be a contributing factor for spermatogenic failure, in addition to the instability of iso/idic Y chromosomes to pass the spermatogenesis process. Possible mechanisms of the formation of the mosaic karyotype and karyotype-phenotype correlations are discussed. The current study highlights that routine karyotype analysis and fluorescent in situ hybridization-based technology are more useful in detecting mosaic chromosomal abnormality, predicting the clinical features of patients during genetic counseling and improving artificial reproductive technologies.