Chromosomal analyses in genetic counseling of patients with developmental and congenital abnormalities from Belém, Pará State, Brazil: a retrospective study of 17 years

Abstract

OBJECTIVE: To present a retrospective study covering 17 years of referral of patients to a public clinical cytogenetic service in Belém, Pará State, located in the Brazilian Amazon. MATERIALS AND METHODS: This study was based on a retrospective survey conducted from 1997 to 2014, considering registered chromosome G-banding results and relating them to information collected during patient evaluation. RESULTS: From a total of 1,580 patients, 730 (46.2%) had chromosomal abnormalities, of which 637 (87.3%) showed numerical alterations. Abnormalities involving autosomal chromosomes were more frequent, 524/730 (71.8%), while alterations in sex chromosomes comprised 28.2% (206). Down's syndrome was the most frequent, 424 (58.1%) of cases, followed by 175 (24.0%) cases of Turner's syndrome, and 25 (3.4%) of Klinefelter's syndrome. Patients with sex chromosome abnormalities were referred at a more advanced age when compared with those having autosomal chromosome abnormalities, with peaks around 11–15 years old (30.1% of cases) and 0–6 months old (40.5%), respectively. CONCLUSION: These findings are very similar to other studies and draw attention to public measures to improve both the quality with regard to diagnosis and the subsequent care of the patient.