Autism spectrum disorder-associated biomarkers for case evaluation and management by clinical geneticists

Abstract

Autism spectrum disorders (ASDs) are neurodevelopmental disorders, usually diagnosed in early childhood and characterized by varying restrictions in communication and social interaction; as well as by atypical, repetitive behaviors including hyperactivity, poor attention, impulsivity, aggression, self-injury, tantrums and unusual responses to sensory stimuli [1]. Furthermore, common conditions often associated with an ASD diagnosis include gastrointestinal disease and dysbiosis [2], autoimmune disease [3] and mental retardation [4]. Based on a recent survey, ASDs occured in at least one in 150 children born in the USA during the early 1990s [5]. In April of 2008, the American College of Medical Genetics issued clinical practice guidelines recommending that clinical geneticists identify the etiology of ASDs and treat patients with the diagnosis. The work-up includes examining and evaluating the patient, the parents and the siblings, in order to establish a definitive etiology. Depending on the etiology, associated medical risks may be identified, which may lead to screening and potential morbidity prevention in patients and other family members. Specific recurrence risk counseling beyond general multifactorial information can be provided, and targeted testing of at-risk family members can be offered. In a number of cases (e.g., metabolic disorders), targeted therapies may be or become available, strongly justifying a medical genetics consultation for all ASD patients [6]. This article examines recognized, clinically available biomarker testing for the evaluation and treatment of ASDs. It will attempt to explain the clinical significance of the findings and, where possible, explore potential treatment options.