The Cytogenetic Examination as a Tool for the Diagnosis of Chromosomal Disorders

Clinically significant chromosomal abnormalities occur in about 1 percent 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 (Araraquara and region), the examination of cariotype (cytogenetic study) for confirmation or exclusion of the diagnostic suspicion of chromosomal 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 Laboratory of Cytogenetic Human of the same institution in 66 cytogenetic studies. In 44 patients (66.6 percent) the results were normal. In 22 (33.3 percent) examinations, alterations were found, meaning that the respective clinical pictures are decurrent of chromosomic alterations. The first cause within alterations noted was Down syndrome with a total of 15 examinations or 68.1 percent, the second cause of chromosomal anomaly was the Turner syndrome where the most important factor is 45, X, where 2 karyotypes of this type or 9.1 percent were found, syndromes as (Eduards syndrome, Patau syndrome, 3p- syndrome, 4p- syndrome and 6p-syndrome) diagnosed in our laboratory appeared less frequently corresponding to 22.7 percent 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 available to the community and contributing significantly to the quality of life of patients. Las anormalidades cromosomicas, clinicamente significativas, se presentan en aproximadamente 1 por ciento de los ninos nacidos vivos. Este trabajo tiene el objetivo de ofrecer a los pacientes y /o a sus familiares el servicio de la Clinica Integrada de la Salud de Uniara (Araraquara y Region), el examen de cariotipo (estudio citogenetico) para la confirmacion o la exclusion de sospecha de anomalias cromosomales diagnosticadas, asi como otorgar informacion (consejo genetico) para la prevencion de las posibles anomalias y /o la repeticion de estas. En un ano y cuatro meses fueron realizados 66 estudios de citogenetica en la Clinica Integrada de Uniara, dirigida por el Laboratorio de Citogenetica Humana de la misma institucion. En 44 pacientes (66,6 por ciento) los resultados fueron normales. En 22 (33,3 por ciento) de los examenes, se encontraron alteraciones, compatibles con alteraciones cromosomicas. La primera causa de anomalias cromosomica fue el sindrome de Down, totalizando 15 examenes (68,1 por ciento), la segunda causa fue el sindrome de Turner, con dos cariotipos (9,1 por ciento) en la forma mas importante 45, X. Por otra parte, se encontro que los sindromes de Eduards, de Patau, 3p-sindrome de Down, sindrome 4p-6p, diagnosticados en nuestro laboratorio, presentaban baja frecuencia de aparicion, representando el 22,7 por ciento de las anomalias estudiadas. Este trabajo permitio realizar un diagnostico preciso de las anomalias cromosomales, principalmente a traves de una tecnica de bajo costo, facil ejecucion y buena confiabilidad, tecnicas que estan disponibles para el examen citogenetico para la comunidad y asi contribuir de manera significativa en la calidad de vida de los pacientes.