[Marker chromosome analysis in Chinese patients with Turner syndrome by fluorescence in situ hybridization].
OBJECTIVE
To identify the origin of marker chromosome of patients with Turner syndrome, and to provide the information for genetic counseling and treatment.


METHODS
The karyotypes of 32 patients with Turner syndrome from 2001 to 2003 at the Center for Diagnosis of Genetic Metabolic Diseases were reviewed. Metaphase chromosome analyses of peripheral blood lymphocytes, G-band and C-band were performed using standard methods. Fluorescence in situ hybridization (FISH) was performed to identify the origin of marker chromosome by using two probes: sex-determining region Y (SRY) for band region Yp11.3 and chromosome enumeration probe for X(CEPX) for band region Xp11.1-q11.1.


RESULTS
3/32(9.4%) patients with Turner syndrome had marker chromosome, the karyotype being 45,X/46,X,mar. Among the 3 marker chromosomes, 2 originated from chromosome X or Y, as identified by the FISH. The origin of the third marker chromosome could not be identified by CEPX and SRY probes.


CONCLUSIONS
The presence of a marker chromosome in Turner syndrome generally implicates a sex chromosome origin. It may also originate from a non-sex chromosome. Therefore, it is necessary to apply X and Y probes simultaneously for marker chromosome detection in Turner patients with monosomy X.
Liang
Yan
Y
Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030 PR China.
Luo
Xiao-ping
XP
D000293:Adolescent; D002871:Chromosome Banding; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping; D014424:Turner Syndrome / Q000175:diagnosis / Q000235:genetics*