Determining the origins and the structural aberrations of small marker chromosomes in two cases of 45,X/46,X, + mar by use of chromosome-specific DNA probes.
A 17-year-old girl (S.M.) and a 13-year-old girl (C.L.) both with Ullrich-Turner syndrome (UTS) were found to have 45,X/46,X, + mar mosaicism. The marker chromosomes in both patients were very small in size. In S.M. the marker chromosome was present in 80% of phytohemagglutinin-stimulated lymphocytes, 28% of skin fibroblasts, and 11-20% of gonadal fibroblasts. In C.L., the small marker chromosome was found in 50% of stimulated lymphocytes. S.M. is of normal height, but C.L. is short. Molecular hybridization with a number of Y-specific DNA probes demonstrated their presence in S.M. but absence in C.L. In situ hybridization with Y-specific and X-centromere-specific DNA probes confirmed the Y origin of the marker chromosome in S.M. and the X origin of the minute chromosome in C.L. Biotinylated centromere and telomere probes were also used for in situ hybridization to show the presence of centromeric and telomeric sequences in the Y-marker chromosome, suggesting that the deletion of this marker chromosome is interstitial.
Lin
C C
CC
Department of Pathology, University of Alberta, Edmonton, Canada.
Meyne
J
J
Sasi
R
R
Bowen
P
P
Unger
T
T
Tainaka
T
T
Hadro
T A
TA
Hoo
J J
JJ
D000293:Adolescent; D015342:DNA Probes; D005260:Female; D005819:Genetic Markers; D006801:Humans; D009030:Mosaicism; D009693:Nucleic Acid Hybridization; D012303:Ring Chromosomes; D014424:Turner Syndrome / Q000235:genetics*; D014960:X Chromosome; D014998:Y Chromosome
D015342:DNA Probes; D005819:Genetic Markers