Early Bilateral Gonadoblastoma in a Young Child with Mosaicism for Turner Syndrome and Trisomy 18 with Y Chromosome.
Mosaic Turner syndrome (TSM) commonly occurs in the form of 45,X/46,XX and 45,X/46,X,i(X)(q10). Mosaicism for a Y chromosome, 45,X/46,XY, has been well documented and is associated with increased risk of gonadoblastoma (GB). To date, there are only six reported cases of TSM with a trisomy 18 karyotype, and only two of these were phenotypically female with 45,X/47,XY,+18 karyotype. We present the case of a phenotypically female infant born with dysmorphic features. G-banded karyotype and interphase FISH of blood showed 45,X in 95% and 47,XY,+18 (trisomy 18) in 5% of cells analysed. However, interphase FISH of buccal cells showed only the presence of the 45,X cell line. Due to the presence of Y chromosome material, elective gonadectomy was performed at 13 months of age. There were bilateral streak ovaries with early evidence of GB bilaterally, a rudimentary uterus and bilateral fallopian tubes with unilateral ectopic adrenal tissue identified histologically. Interphase FISH of the gonadal tissue was similar to the blood findings with 45,X in 86% of cells and 47,XY,+18 in 14% of cells analysed. This case highlights a rare karyotype of TSM and trisomy 18 in the same patient and is the first reporting the associated finding of bilateral GB.
Department of Paediatrics and Child Health, Cork University Hospital, Cork, Ireland.
Jayne M
JM
MacMahon
Maureen J
MJ
O'Sullivan
Michael
M
McDermott
Feargal
F
Quinn
Thomas
T
Morris
Andrew J
AJ
Green
David R
DR
Betts
Susan M
SM
O'Connell
D002887:Chromosomes, Human, Pair 18 / Q000235:genetics / Q000378:metabolism; D041322:Chromosomes, Human, Y; D005260:Female; D018238:Gonadoblastoma / Q000097:blood / Q000235:genetics / Q000601:surgery; D006801:Humans; D007223:Infant; D009030:Mosaicism; D014314:Trisomy / Q000235:genetics; D000073842:Trisomy 18 Syndrome; D014424:Turner Syndrome / Q000097:blood / Q000235:genetics / Q000601:surgery