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.