Ovarian reserve evaluation in a woman with 45,X/47,XXX mosaicism: A case report and a review of literature

BACKGROUND: Turner syndrome (TS) is a common chromosomal disorder affecting approximately 1:2,500 live female births. Mosaic 47,XXX karyotype is found in 3%–4% of TS patients. TS phenotype in rare 45,X/47,XXX mosaicism patients is milder than in classic TS, however their ovarian function, especially in the mature age, has not been described in detail. METHODS: A case report and literature review. RESULTS: A 30‐year‐old woman with menstrual irregularity and primary infertility presented with short stature and multiple nevi on the face without other common TS clinical features. She had spontaneous puberty and menarche but diminished ovarian reserve at the age of 30. Fluorescence in situ hybridization (FISH) indicated 45,X/47,XXX mosaicism, which was once misdiagnosed as 45,X monosomy. Literature review revealed the prevalence of short stature in only 64.3% of 45,X/47,XXX mosaicism cases, that is, much less frequently than in pure 45,X monosomy. The risk of premature ovarian insufficiency in 45,X/47,XXX mosaicism patients is higher, and ovarian failure is usually observed at around 30 years of age. CONCLUSION: FISH should be recommended to evaluate low proportion mosaicism in similar cases. Due to the risk of ovarian failure, fertility preservation for patients with 45,X/47,XXX mosaicism at a younger age must be considered.