RESUMEN
BACKGROUND: In patients with Turner syndrome, it is known that the presence of Y-specific sequence is correlated with the risk of gonadoblastoma development. Y-specific sequence are frequently present in marker chromsome which can not be easily identified by cytogenetic method, because it is very small in size and unstable during mitosis. So, in this study, karyotype of 30 patients with Turner syndrome analyzed by cytogenetic method and the presence of Y-specific sequence was identified by polymerase chain reaction (PCR). METHODS: Cytogenetic analysis was performed by Phytohemaggulutinin (PHA)-stimulated lymphocyte culture and G-banding by Wright stain without trypsin treatment. Four Y-specific sequences were amplified by PCR using specific primer for Sex determination on Y (SRY), Ameglonin like gene (AMGL), Y1.1-1.2 repeat sequence (Y1.1-1.2) and B fragment of DYZ1 (DYZ1-B). DNAs for PCR analysis were extracted from peripheral blood lymphocytes of preserved cell pellets which were harvested for cytogenetic analysis. RESULTS: Cytogenetic analysis revealed various karyotypes in Turner syndrome such as 45,X, 46,X,i(X)(q10), 46,X,del(X) including four cases of 46,X,+mar and three cases of 46,X,+r. It is could not identify Y-chromosome in this 30 patients with Turner syndrome. By PCR, three patients (10%) with Turner syndrome had at least one Y-specific sequence; one case of 45,X karyotype was amplified in SRY; one case of 45,X[9]/46,X,i(X)(q10)[1]/46,XX[10] was amplified in AMGL, Y1.1-1.2; one case of 46,X,i(X)(q10) was amplified in SRY, AMGL and Y1.1-1.2. None of case was amplified in DYZ1-B. CONCLUSIONS: PCR for amplification of Y-specific sequence was thought to be useful in detection of Y-chromosome, which might be helpful in early diagnosis of gonadoblastoma in patients with Turner syndrome.