Discordant growth pattern and ovarian function in monozygotic twins with 45,X/46,XX mosaicism.
BACKGROUND
We report on phenotypically discordant female monozygotic twins with 45X/46,XX mosaicism in both lymphocytes and fibroblasts.


RESULTS
At 11.5 years, twin A was prepubertal, her height was 126.8 cm (-3.15 SD), bone age (BA) 9.7 years (TW2), FSH 47 IU/l and IGF-I 280 ng/ml (-0.89 SD), but twin B was pubertal (P2, B3), her height was 143.4 cm (-0.92 SD), BA 13.6 years (TW2), FSH 3.4 IU/l and IGF-I 380 ng/ml (-0.21 SD). One year later, twin A had grown 11.1 cm due to growth hormone therapy and had IGF-I 1,400 ng/ml (+5.91 SD), whereas the growth velocity of twin B (no therapy) was 5.9 cm, IGF-I 540 ng/ml (+0.57 SD) and she started regular menstruation at 12.1 years.


CONCLUSIONS
To our knowledge, this is the first report on monozygotic twins with Turner mosaicism in both lymphocytes and fibroblasts who developed a discordant phenotype probably due to an unequal distribution of the two cell lines in distinct tissues.
Lebl
J
J
Department of Pediatrics, 3rd School of Medicine, Charles University, Prague, Czech Republic. lebl@fnkv.cz
Zahradníková
M
M
Vlasak
I
I
Neuhuber
F
F
D002648:Child; D004200:Diseases in Twins; D004958:Estradiol / Q000627:therapeutic use; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006130:Growth Disorders / Q000188:drug therapy / Q000235:genetics*; D019382:Human Growth Hormone / Q000627:therapeutic use; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood; D009030:Mosaicism; D010641:Phenotype; D011627:Puberty; D014424:Turner Syndrome / Q000235:genetics*; D014430:Twins, Monozygotic
D019382:Human Growth Hormone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone