الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Turner syndrome is the most common chromosomal abnormality in females, affecting 1:2,500 live female birth. It is characterized by short stature, gonadal dysgenesis and a variety of somatic features and major organ malformations. About 50% of the patients have a 45, X karyotype, while the remainder have structurally abnormal sex chromosomes or mosaicism including 45,X/46,XY. Cytogenetic technique detects Y chromosome mosaicism in about 5.5% of TS. The introduction of PCR technique has revealed the existence of hidden Y-chromosome material not detected by cytogenetic examination. Those with Y chromosomal material are at increased risk for developing gonadoblastoma, which has considerable malignant potential. Currently, it is recommended to perform prophylactic gonadectomy in TS patients with Y-chromosome material. The aim of this study was to detect the presence of Y chromosome material in TS patients. This will allow early and accurate detection of patients at high risk of gonadal tumor development and consequently, their proper management.
This study was carried out on twenty patients with TS, diagnosed by karyotype.
All cases were subjected to careful history taking, complete clinical examination, abdominal and pelvic songraphy, hormonal assays, cytogenetic examination, molecular studies for identification of Y-chromosome material by PCR amplification using DYZ3 and SRY specific primers. Lastly patients and their families were offered proper genetic counseling.
Examination of studied cases revealed that TS syndrome is characterized by short stature in 90 % of cases, gonadal hypoplasia in 100% of cases and a variety of somatic features as neck webbing in 70% of cases, cubitus valgus in 60% of cases and short fourth and fifth metacarpals in 45% of cases.
Cytogenetic examination of all cases revealed 45% of patients have classical 45, X karyotype, 10% of patients have structurally abnormal X and 45% of patients have mosaic karyotype.
PCR screening for Y-chromosome material using DYZ3 and SRY specific primers was done in all cases and revealed Y chromosome material in 4 patients. Three of these patients had 45, X karyotype that did not suggest the presence of Y-chromosome material, whereas the remaining patient had a marker chromosome (45, X/ 45, X+mar) which suggest the presence of Y chromosome material.