Cytogenetic Investigation in Patients with Clinical Suspicion of Genetic Syndrome in Manaus, Brazil

Chromosomal alterations can cause a number of diseases; therefore, early detection of these alterations is fundamental in the prevention and treatment of various abnormalities. In this sense, the objective of this study was to perform cytogenetic analysis of patients with phenotypic characteristics not yet clarified in order to determine the frequency of chromosomal alterations in patients treated in the public health system in Manaus, Brazil. A total of 98 patients with clinical suspicion of genetic syndrome were referred to the public health system in Manaus, Amazonas state. Genetic analyses were performed from lymphocyte culture and subsequent G-banding. Patient data were obtained through referral files and chromosomal a Analyses. Of the 98 karyotypes analyzed, 65 (66.3%) presented normal karyotype, 18 (18.4%) presented chromosomal alterations and 15 (15.3%) were inconclusive. Of the alterations found, 11 (61.1%) corresponded to alterations of the numerical type and 7 (38.9%) of the structural type. Of the chromosomal alterations identified, the one with the highest frequency was aneuploidy, which was significantly represented by 9 patients with Down's syndrome, and different karyotypic mechanisms related to this syndrome were observed. There was also one case of deletion, one case of pericentric inversion, and two involving the sex chromosomes. The etiological confirmation of congenital anomalies is extremely important for the patient's prognosis, and it is necessary to invest in cytomolecular tests, such as FISH and microarray in order to increase the rate of diagnosis.