Y chromosome sequences in Turner's syndrome: association with virilization and gonadoblastoma.
The presence of Y chromosome fragments in patients with Turner's syndrome is known to increase the risk of gonadoblastoma and virilization. Y chromosome material is detected in up to 6% of patients with Turner's syndrome by karyotype. By DNA analysis, Y chromosome sequences have been reported in 0-60% of patients. The putative gonadoblastoma gene has been mapped to the pericentromeric region of the Y chromosome increasing the interest in studying these sequences.


OBJECTIVE
1. To determine the frequency of occult Y chromosome sequences in patients with Turner's syndrome. 2. To analyze the clinical implications of Y sequences detected by karyotype and occult Y sequences.


METHODS
Cross-sectional study of 58 patients with Turner's syndrome (30 45,X; two with structural anomalies; 26 mosaic [two of whom were 45,X/46,XY]). SRY, TSPY and DYZ3 sequences were amplified by PCR using genomic DNA from peripheral blood.


RESULTS
All three Y chromosome sequences were found in one out of 56 patients whose karyotype was not suggestive of having Y chromosome material and in one patient with 45,X/46,Xr(X) karyotype. The patients with the ring chromosome and 45,X/46,XY karyotype underwent surgery and were found to have a gonadoblastoma and dysgerminoma. The four patients with Y chromosome material had non-virilized female genitalia.


CONCLUSIONS
Analysis by PCR was more sensitive in detecting Y chromosome sequences than conventional karyotype. The presence of Y material was not associated with virilization. We confirmed the association of Y fragments and gonadoblastoma at an early age.
Department of Pediatrics and Clinical Laboratory Service, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Mancilla
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Poggi
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G
Repetto
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H
Rumié
H
H
García
F
F
Ugarte
S
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Hidalgo
A
A
Jara
S
S
Muzzo
E
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Panteón
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I
Torrealba
A
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Foradori
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Cattani
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D018797:Cell Cycle Proteins; D002648:Child; D002675:Child, Preschool; D002677:Chile; D041322:Chromosomes, Human, Y; D003430:Cross-Sectional Studies; D020732:Cytogenetic Analysis / Q000379:methods; D004268:DNA-Binding Proteins; D004407:Dysgerminoma / Q000150:complications / Q000175:diagnosis / Q000235:genetics; D005260:Female; D018238:Gonadoblastoma / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D006066:Gonads / Q000473:pathology / Q000601:surgery / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000166:cytology; D009030:Mosaicism; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction / Q000379:methods; D012303:Ring Chromosomes; D012729:Sex Chromosome Aberrations; D051876:Sex-Determining Region Y Protein; D013997:Time Factors; D014157:Transcription Factors; D014424:Turner Syndrome / Q000150:complications* / Q000175:diagnosis / Q000235:genetics*; D014770:Virilism / Q000150:complications* / Q000175:diagnosis
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C497745:SRY protein, human; D051876:Sex-Determining Region Y Protein; C497749:TSPY1 protein, human; D014157:Transcription Factors