Ambiguous genitalia, 45,X/46,XY mosaic karyotype, and Y chromosome microdeletions in a 17-year-old man

Abstract

Objective: To describe clinical and laboratory features of a patient with 45,X/46,XY mosaic karyotype and Y chromosome microdeletions and to discuss the diagnostic problems in his management. Design: Case report. Setting: University department. Patient(s): A 17-year-old man with ambiguous genitalia, 45,X/46,XY mosaic karyotype, and Y chromosome microdeletions. Intervention(s): Testicular ultrasonography, karyotype, open testicular biopsy, polymerase chain reaction (PCR) screening for cystic fibrosis, PCR screening for Y chromosome microdeletions in peripheral blood and testicular tissue, and reverse transcriptase PCR in testicular tissue for Y chromosome microdeletions. Main Outcome Measure(s): Avoidance of dissemination of testicular cancer. Result(s): The patient was referred for bilateral orchiectomy. Conclusion(s): 45,X/46,XY mosaic karyotype is associated with a broad spectrum of phenotypes that includes female with Turner syndrome, male with mixed gonadal dysgenesis, male pseudohermaphroditism, and apparently normal male. Microdeletions of the long arm of the Y chromosome may be associated with Y chromosomal instability, leading to formation of 45,X cell lines. 45,X/46,XY males carry an increased risk for gonadal tumors and must be followed closely.