Autism spectrum disorder (ASD): from genetic classification to molecular diagnosis

Abstract

Autism Spectrum Disorder (ASD) is characterized by persistent sociocommunicative deficits in conjunction with repetitive and restricted behavioral patterns. With the progress in molecular biology and genetics, important tools have emerged that contribute to its genetic knowledge and diagnosis. Thus, this review aims to address the genetic classification of ASD and review the diagnostic advances of the disorder based on molecular biology techniques. For this, a literature review was conducted, using databases such as National Library of Medicine (PUBMED), Scientific Electronic Library Online (SCIELO), recommending articles from 2013 to 2020. Based on the results achieved, the genetic classification of ASD in syndromic and nonsyndromic forms arose from the need to look at the condition from the perspective of the genetic causes involved. As for the diagnostic advances, techniques such as Microarray Chromosome Analysis, karyotype, research for fragile X and sequencing of MECP2 and PTEN genes, are visualized as complementary tools for the clinical diagnosis of ASD.  Finally, we conclude that the genetic classification of ASD highlights the importance of considering genetic issues to improve the knowledge of the disorder, since most current diagnostic guidelines are based exclusively on the patient's clinical condition, excluding genetic aspects already proven to be related to the disorder. Considering the molecular diagnosis of ASD, among its advances and perspectives, molecular biology techniques can contribute to the etiological identification of the case, making genetic counseling and clinical diagnosis more efficient.