BACKGROUND:

Approximately 45% of patients with Turner syndrome have monosomic line 45, X. The existence of the Y chromosome in mosaics corresponds to 2 to 5% of the cases, the severity of the phenotype is related to the percentage and distribution of normal cells, it is even estimated that 90% of mosaic presentations may not have diagnosis.

OBJECTIVE:

To present an atypical case of a young adult with Turner syndrome in mosaic 45,X / 47,XYY

CLINICAL CASE:

A 27-year-old woman visits the University Hospital of Santander for a history of primary amenorrhea, normal female appearance, average height and weight for Colombian population, Tanner 3 breasts and external genitalia Tanner 5. Magnetic resonance imaging reports uterine hypoplasia, ovaries and discards a pituitary tumor. High-resolution karyotype diagnoses Turner mosaic syndrome 45,X [60%] / 47,XYY [40%].

CONCLUSION:

Turner's syndrome should be suspected in women with primary amenorrhea and low stature, however, mosaic conditions may delay their diagnosis until adulthood due to their phenotypic variety, up to 90% of the mosaics can reach no have diagnosis.