[Down-Turner syndrome (45,X/47,XY,+21): case report and review].
We report the case of a 3-yr-old boy with Down-Turner mosaicism and review the previous reports of Down-Turner syndrome with documented karyotyping and clinical features. The patient showed clinical features of Down syndrome without significant stigma of Turner syndrome. Cytogenetic analysis of peripheral blood preparations by using G-banding revealed mosaicism with 2 cell lines (45,X[29]/47,XY,+21[4]). FISH analysis revealed that 87.5% of the cells had monosomy X karyotype and 12.5% of the cells had XY karyotype; trisomy 21 was only detected in the Y-positive cells. We suggest that additional cells should be analyzed and molecular genetic studies should be conducted to rule out double aneuploidy when karyotypes with sex chromosome aneuploidies and mosaicism are encountered, as in our case of Down syndrome mosaic with sex chromosome aneuploidy.
Ryu
Sook Won
SW
Department of Laboratory Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
Lee
Goeun
G
Baik
Cheong Soon
CS
Shim
Sung Han
SH
Kim
Jin Tack
JT
Lee
Jung Soo
JS
Lee
Kyung A
KA
D000782:Aneuploidy; D002675:Child, Preschool; D002871:Chromosome Banding; D002891:Chromosomes, Human, Pair 21; D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D004314:Down Syndrome / Q000150:complications / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D014314:Trisomy; D014424:Turner Syndrome / Q000150:complications / Q000235:genetics*