The Cytogenetic Examination as a Tool for the Diagnosis of Chromosomal Disorders Examinación Citogenética como Herramienta para el Diagnóstico de los Desórdenes Cromosómicos

SUMMARY: Clinically significant chromosomal abnormalities occur in about 1% of children born alive. The objective of this work was to offer the patients and the families in the community for the service of the Integrated Clinic of Uniara Health (Ara raquara and region), the examination of cariotype (cytogenetic study) for confirmation or exclusion of the diagnostic suspicion of chromoso mal abnormalities as well as information (genetic counseling) for the prevention of occurrence and/or recurrence of these anomalies . In the period of one year and four months these were carried out in the Integrated Clinic of Uniara Health and directed for the Labora tory of Cytogenetic Human of the same institution in 66 cytogenetic studies. In 44 patients (66.6%) the results were normal. In 22 (33. 3%) examinations, alterations were found, meaning that the respective clinical pictures are decurrent of chromosomic alterations. T he first cause within alterations noted was Down syndrome with a total of 15 examinations or 68.1%, the second cause of chromosomal anom aly was the Turner syndrome where the most important factor is 45, X, where 2 karyotypes of this type or 9.1% were found, syndromes as (Eduards syndrome, Patau syndrome, 3p- syndrome, 4p- syndrome and 6p-syndrome) diagnosed in our laboratory appeared less freque ntly corresponding to 22.7% of the studied anomalies. The work carried out constitutes a necessary diagnosis of the main chromosomal abnormalities through a low cost technique; it can be carried out easily and is reliable, making the cytogenetic examination av ailable to the community and contributing significantly to the quality of life of patients.