Combined aCGH and Exome Sequencing Analysis Improves Autism Spectrum Disorders Diagnosis: A Case Report.

Background and

Objectives

The development and standardization of genome-wide technologies able to carry out high-resolution, genomic analyses in a cost- and time-affordable way is increasing our knowledge regarding the molecular bases of complex diseases like autism spectrum disorder (ASD). ASD is a group of heterogeneous diseases with multifactorial origins. Genetic factors seem to be involved, albeit they remain still largely unknown. Here, we report the case of a child with a clinical suspicion of ASD investigated by using such a genomic high-resolution approach. Materials and

Methods

Both array comparative genomic hybridization (aCGH) and exome sequencing were carried out on the family trio. aCGH was performed using the 4 × 180 K SurePrint G3 Human CGH Microarray, while the Human All Exon V7 targeted SureSelect XT HS panel was used for exome sequencing.

Results

aCGH identified a paternally inherited duplication of chromosome 7 involving the CNTNAP2 gene, while 5 potentially clinically-relevant variants were identified by exome sequencing.

Conclusions

Within the identified genomic alterations, the CNTNAP2 gene duplication may be related to the patient's phenotype. Indeed, this gene has already been associated with brain development and cognitive functions, including language. The paternal origin of the alteration cannot exclude an incomplete penetrance. Moreover, other genomic factors may act as phenotype modifiers combined with CNTNAP2 gene duplication. Thus, the case reported herein strongly reinforces the need to use extensive genomic analyses to shed light on the bases of complex diseases.