A case of 45,X/47,XXX mosaic Turner syndrome: Clinical manifestations and effect of growth hormone treatment

In Turner syndrome (TS), 45,X/47,XXX mosaicism is a rare genotype. Due to its low frequency, the clinical features and prognosis are not clearly known. A 10-year-old girl was diagnosed with 45,X/47,XXX mosaicism TS and presented with short stature. She did not show any other TS phenotypic features, except for short stature, and developed spontaneous puberty and menarche, although she had unilateral ovarian agenesis. She achieved a significant growth improvement following growth hormone treatment. Since 45,X/47,XXX mosaic TS shows different gonadal function from that of classic TS, it is necessary to conduct surveillance for premature ovarian insufficiency.