• Panel 1: For individuals with ASD and macrocephaly

                      GenomeDx 105k high-resolution microarray/PTEN/MECP2/CDKL5‡

                      ‡Check box on submission form if CDKL5 testing is clinically indicated
                        (infantile spasms/seizures).
 

• Panel 2: For individuals with ASD and normal or small head size

                     GenomeDx 105k high-resolution microarray/MECP2/CDKL5‡

                      ‡Check box on submission form if CDKL5 testing is clinically indicated
                        (infantile spasms/seizures).
 

• Panel 3: “á la carte” gene testing for individuals with syndromic autism
                 or specific suspected genetic syndrome(s)

                      Any test or combination of tests can be ordered ‘a la carte’ if indicated.

Autism spectrum disorders (ASDs) are a group of severe neurodevelopmental disorders with rising prevalence, in which individuals show deficits in social interaction, impaired communication, repetitive behavior and restricted interests and activities. ASDs include several clinically defined conditions, of which pervasive developmental disorder (not otherwise specified) and autistic disorder (‘classic’ or ‘non-syndromic’ autism) are the most common. Less frequent are Asperger syndrome, Rett syndrome (which typically occurs in females), and childhood disintegrative disorder. Several atypical variants of Rett syndrome have also been reported. Approximately 24% of individuals with autism have macrocephaly (head circumference above the 98th percentile) and 15.1% have microcephaly (head circumference below the 3rd percentile). Autistic features may also be present in patients with a defined genetic syndrome, rare metabolic disorders, and other disorders.
The etiology of ASD is complex, including multiple genetic, epigenetic and environmental factors. At least 10%-20% of individuals with a clinical diagnosis of Autism/ASD are expected to have an identifiable genetic cause. Most common is a genomic gain (duplication) or loss (deletion) of chromosomal material that can be identified by genome-wide oligonucleotide microarray analysis, such as GenomeDx. Other causes are mutation in one of the following genes, which are included in AutismDx testing: PTEN, MECP2, and CDKL5.
 

What is AutismDx?                                                                                                         

AutismDx testing is offered as tiered genetic testing approach to identify the most common genetic causes of Autism/ASD in individuals in whom a diagnosis of Fragile X has already been excluded. AutismDx testing includes three different Autism Panels, which are tailored to the clinical characteristics of an affected individual. Each Autism Panel combines genome-wide microarray analysis with DNA sequence analysis of those disease genes that are most suitable for individuals within a distinct subgroup. Each Autism Panel comprises several sequential tiers of analysis (reflex testing)*, thus providing the highest possible diagnostic yield and most cost-effective testing strategy.

Other resources

• GeneReviews
• http://www.cdc.gov/ncbddd/autism/actearly/autism.html
• http://www.acmg.net/
• http://www.autismspeaks.org/

Relevant Articles:

Fombonne E. J Clin Psychiatry 2005; 66 Suppl. 10:3-8;
Fombonne et al., J Autism Dev Disord. 1999;29(2):113-9;
Shaefer GB & Mendelssohn NJ. Genet Med 2008; 10:4-12;
Abrahams BS & Geschwind DH. Nat Genet Rev 2008; 9:341-355;
Cohen D et al., J Aut Dev Dis 2005; 35:103-1116;
Marshall CR et al., Am J Hum Genet. 2008; 82:477-88;
Jacquemont ML et al., J Med Genet 2006; 43:843-849; 
Herman et al. Genet Med 2007:9:258-274;
Butler et al., J Med Genet 2005:42:318-321;
Scala et al., Am J Med Genet A. 2007; 43:2275-2784;
delGaudio et al., Genet Med 2006; 784-792;
Archer HL et al. J. Med. Genet. 43: 729-734, 2006;
Tao J et al., Am. J. Hum. Genet. 75: 1149-1154, 2004