Cytogenetic Diagnosis and Analysis of the Clinical Profile of Individuals with Non-down Syndrome Intellectual Disability

Abstract

Abstract:Chromosomal alterations are the main causes of genetic diseases. One of the characteristics of certain genetic syndromes is ID (intellectual disability) presented by the individual in varying degrees. The study of the ID, its etiology, association or not with chromosomal abnormalities and a clinical diagnosis associated with the examination of karyotype are important aspects to consider when providing genetic counseling for families. Due to the lack of similar studies and of easy access to cytogenetic services for the Amazonian population, this study aimed to contribute to the advancement of this line of study in the state, analyzing the karyotype of individuals with ID, not Down Syndrome treated at the APAE-Manaus and identifying the main types of chromosomal alterations in the individuals analyzed. Analyzes were performed of the clinical diagnosis through investigation of the data from the interview and medical records as well as analysis of the karyotype of 31 patients with non-Down syndrome ID, attended in the APAE-Manaus. Of these subjects, 20 were female and 11 male. The results showed only 2 cases of chromosome abnormalities are detectable by classical cytogenetics, one of mosaic Turner syndrome and one a heterochromatic variant. It is therefore necessary to complement the study with the addition of molecular techniques for the investigation of microdeletions and/or other alterations not detectable through the banding technique, mainly for individuals whose dysmorphisms indicate a suspected syndrome.

Investigation of chromosomal alterations in patients with Alzheimer's disease in the state of Amazonas, Brazil

“…Chromosomal syndromes resulting from the loss of X can influence the cognitive capacity of the individual, and intellectual deficiency is the main characteristic of these syndromes 23,24 . Karyotype analysis performed in patients with non-Down syndrome intellectual disability, attending the APAE-Manaus, identified one patient with mosaic Turner syndrome (45,X/46,XX) detected by classical cytogenetics, demonstrating a correlation between the loss of X chromosome and intellectual deficiency 25 . Although a relationship between X chromosome loss and cognitive/intellectual impairment in certain diseases is evident, in the present study, no direct evidence of a correlation between the X chromosome loss and the degree of cognitive impairment (MMSE test) was found in AD patients.…”