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

Fertil Steril. 2001 Dec;76(6):1261-3. doi: 10.1016/s0015-0282(01)02877-1.


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.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Biopsy
  • Chromosome Aberrations*
  • Chromosome Deletion
  • DNA, Complementary / chemistry
  • Humans
  • Karyotyping
  • Male
  • Mosaicism*
  • RNA / chemistry
  • RNA / isolation & purification
  • Reverse Transcriptase Polymerase Chain Reaction
  • Testis / abnormalities*
  • Testis / diagnostic imaging
  • Ultrasonography
  • Y Chromosome*


  • DNA, Complementary
  • RNA