Evaluation of sex chromosome aneuploidies in women with Turner's syndrome by G-banding and FISH. A serial case study.
OBJECTIVE
To evaluate sex chromosome aneuploidies in patients with Turner's syndrome using two cytogenetic techniques.


METHODS
A sample of 35 women with a clinical suspicion of Turner syndrome was examined in the Hospital of Obstetrics and Gynecology, Instituto Mexicano del Seguro Social, Monterrey, Mexico. They were subjected to a conventional cytogenetic technique with G-banding and to fluorescence in situ hybridization (FISH) using a specific alpha satellite X chromosome (DXZ1) and specific alpha satellite Y chromosome (DYZ1).


RESULTS
Using both techniques, 17 cases (48.57%) showed the same karyotype. Using FISH: (1) in 8 cases the presence of the Y chromosome was confirmed, (2) in 18 cases (51.43%) a new cell line was identified, (3) in 2 cases (5.71%) the derivative X was clarified, and (4) in 3 cases (8.57%) the origin of the chromosome markers (1 of X chromosome and 2 of Y chromosome) was delineated. FISH highlighted the differences between the initial diagnosis, based on G-banding, and the final diagnosis, determined by specific probes for the X and Y chromosomes.


CONCLUSIONS
FISH is a useful tool in the detection of low-frequency cell lines and identification of the nature and origin of derivative chromosomes and unknown chromosome markers that have important implications for the treatment of patients with Turner's syndrome.
Cortés-Gutiérrez
Elva I
EI
Genetics Division, School of Nursing, Northeast Center for Biomedical Research, Mexican Institute of Social Security, School of Biological Sciences, Ignacio Morones Prieto, Nuevo Leon, Mexico. elvairenecortes@hotmail.com
Cerda-Flores
Ricardo M
RM
Silva-Cudish
Julie B
JB
Dávila-Rodríguez
Martha I
MI
Hernández-Herrera
Ricardo
R
Leal-Garza
Carlos H
CH
D000293:Adolescent; D000328:Adult; D002648:Child; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping / Q000379:methods; D011237:Predictive Value of Tests; D012730:Sex Chromosomes / Q000235:genetics; D014424:Turner Syndrome / Q000235:genetics*