Phenotype, ovarian function, and growth in patients with 45,X/47,XXX Turner mosaicism: implications for prenatal counseling and estrogen therapy at puberty.

Objective: Our objective was to determine whether girls with the rare Tur-ner 45,X/47,XXX mosaic karyotype are less severely affected than girls with 2 commoner karyotypes.

Study Design: We evaluated growth status, phenotype, and ovarian function in 7 girls with 45,X/47,XXX mosaicism, age-matching each with 2 girls with 45,X and 1 with 45,X/46,Xi(X)(q10) karyotypes.

Results: For the index, 45,X, and 45,X/46,Xi(X)(q10) groups, respectively, the median/mean height SD score at the start of growth hormone therapy/comparable age was -2.0 (-1.2), -2.3 (-2.4), and -2.6 (-2.6), cardiac anomalies were identified in 0 of 7, 4 of 14, and 1 of 7, renal abnormalities in 0 of 7, 4 of 14, and 3 of 7, middle ear problems in 2 of 7, 11 of 14, and 4 of 7, and special educational needs in 0 of 7, 3 of 14, and 1 of 7. Complete spontaneous puberty with menarche was seen in all but 1 girl older than 12 years in the index group compared with only 1 girl in the comparison groups. Ovarian tissue was identified in 6 of 7, 0 of 14, and 1 of 7 girls, and the mean follicle-stimulating hormone was 6, 25, and 21 U/L, respectively.

Conclusion: Girls with 45,X/47,XXX karyotype are mildly affected, with good preservation of ovarian function. This result has important implications for prenatal counseling and the need for estrogen therapy at puberty.