Mosaic ring X chromosome in a case of secondary amenorrhea.

OBJECTIVE

To report an unusual case of secondary amenorrhea in a 17-year-old adolescent with normal sexual development who proved to have a karyotype 46,XX/46,X,+ringX/47,XX,+ringX.

DESIGN

Case report.

SETTING

Hospital, tertiary level of clinical endocrine care.

PATIENT(S): A 17-year-old patient with secondary amenorrhea and normal sexual characteristics with no stigmata of Turner syndrome.

INTERVENTION(S): Clinical history, hormonal markers, cytogenetic analysis.

MAIN OUTCOME MEASURE(S): Cytogenetic analysis by G-banding technique, multicolor fluorescence in situ hybridization, and multicolor banding analysis on peripheral blood lymphocytes.

RESULT(S): The presence of mosaicism in 12% of metaphases indicating a ring X chromosome with one or two normal X chromosomes, forming a karyotype 46,XX/46,X, +ringX/47,XX,+ringX.

CONCLUSION(S): Our findings indicate the necessity for cytogenetic studies in certain cases of amenorrhea. This is a very rare karyotype in patients with secondary amenorrhea.