Crypt Y chromosome fragment resulting from an X;Y translocation in a patient with premature ovarian failure

Objective

To identify a cryptic Y chromosome fragment that resulted from a X;Y translocation in a patient with premature ovarian failure (POF) and analyze the karyotype–phenotype correlation.

Design

Case report.

Setting

A university-based reproductive medicine center.

Patient(s)

A 33-year-old woman with POF.

Intervention(s)

Karyotyping analysis, comparative genomic hybridization, fluorescence in situ hybridization, and polymerase chain reaction (PCR) analysis for the patient.

Main Outcome Measure(s)

Karyotype determination of the patient.

Result(s)

The patient was suspected to carry an abnormal X chromosome by traditional cytogenetic analysis. A Y chromosome hybridization signal was found in the patient's genome by comparative genomic hybridization analysis. The fluorescence in situ hybridization result showed that the Y chromosome material resulted from a translocation between Xq and Yq. Using the specific sequence-tagged sites, the breakpoints on the X and Y chromosomes were located at Xq26.3 and Yq11.223, respectively. Combined with chromosome G banding and C banding, the karyotype of the patient was determined as 46,X,der(X)t(X;Y) (q26.3;q11.223).

Conclusion(s)

The advanced molecular cytogenetic techniques are helpful to detect cryptic chromosome aberrancies in patients with POF. This rare case supports that Xq26-q28 is the critical region of POF, and is helpful to analyze the risk of gonadoblastoma in patients with POF with Y chromosomal material.

Key Words: Premature ovarian failure, comparative genomic hybridization, fluorescent in situ hybridization, X/Y translocation