A Case of Mosaic 45,X/46,XY Infertile Man with an AZF Deletion

Objectives: The frequency of chromosomal abnormalities is approximately 15% in azoospermic men. 45,X/46,XY mosaicism or mixed gonadal dysgenesis is associated with phenotypes ranging from normal male development to clinical signs of Turner syndrome. Y chromosome with structural chromosomal abnormalities is unstable and can be lost during mitosis. Therefore, structural chromosomal abnormalities of Y chromosome can be observed in individuals with 45,X/46,XY mosaic karyotype. We report here a mosaic 45,X/46,XY infertile man with azoospermia factor (AZF) deletion and normal male phenotype. Methods: Karyotype analysis of peripheral blood was performed for the azospermic and infertile male. We detected 45,X/46,XY mosaicism. So we performed FISH using centromere probes for the X and Y chromosomes. Y chromosome microdeletions were investigated by polymerase chain reaction assays. Also we investigated the AZF and sex-determining region Y (SRY) microdeletions for patient's father. Results: Our patient was a 31-year-old male who has been married for 7 months; the couple were distant relatives. The patient was referred to Medical Genetics department from Urology with azoospermia and infertility diagnosis. The physical examination was normal except sparse eyebrows. Karyotype analysis was 45,X[20]/46,XY[39]. After applying XY centromeric FISH analysis, we detected 63% XY and 37% X interphase cells. Molecular analysis revealed that AZFa and SRY regions were present, but AZFb, AZFc, and AZFd regions were deleted. The father's results were normal. Conclusion: 45,X/46,XY mosaic karyotype and AZF deletion were not hereditary. Genetic counseling was given to the family. We concluded that wide AZF region deletions caused 45,X/46,XY mosaic karyotype status in our patient to reveal unstable Y chromosome during mitosis . Our aim is to emphasize that Y chromosome microdeletions should be analyzed in 45,X/46,XY mosaic karyotype detected in infertile men with normal phenotype.