CEDIE   05498
CENTRO DE INVESTIGACIONES ENDOCRINOLOGICAS "DR. CESAR BERGADA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cytogenetic Characterization by Fluorescent In Situ Hybridisation (FISH) of a Structurally Abnormal Y Chromosome in a Patient with Turner Syndrome.
Autor/es:
DEL REY G,; STIVEL M,; COCO R,; VENARA M,; DE BELLIS R,; BOYWITT A,; CHEMES H.
Lugar:
Mar del Plata, Argentina
Reunión:
Congreso; XIX Reunion de la Soc. Latinoamericana de Endocrinologia Pediatrica; 2007
Institución organizadora:
Sociedad Latinoamericana de Endocrinología Pediátrica
Resumen:
The Turner syndrome (TS) is caused by total or partial haploinsufficiency of one sex chromosome.Approximately half of the patients have a 45,X karyotype.Others are mosaics for a second cell line containing either a normal or a structurally abnormal X.In 6% of the patients a Y chromosome is present which determines an increased risk of developing germ cell tumors.PCR is used to identify the presence or absence of specific Y sequences in patients with TS,but such analysis does not provide information about the structure of the Y chromosome.Objective:To report the clinical and cytogenetic molecular findings in a patient with TS.Patient and Methods:Adolescent referred at 17.3 years with severe short stature. Height:122cm,(–2.92 SDS for Turner standard),without pubertal development.The examination revealed typical TS stigmata.Bone age:11 years.Celiac disease was confirmed by intestinal biopsy.Chromosome analysis and FISH were carried out on peripheral lymphocytes.Results:Karyotype with GTG and CBG banding showed a mosaic 45,X [16]/46,X,i(Yq)[14].FISH evidenced  two SRY signals (Yp11.2).This indicates that in addition to Yq duplication there was a partial double copy of Yp caused by a break/join at the distal tip of Yp.On gonadectomy, bilateral streaks (non-neoplastic),oviduct and Wolffian remnants were found.Conclusion:FISH is a useful technique for determining the structure of abnormal chromosomes.In this mosaic karyotype,the SRY was insufficient to induce testicular development.The intact pericentromeric region (Yq) was important to prevent gonadoblastoma development.