RESUMO
<p><b>OBJECTIVE</b>To explore the clinical features and genetic mutation in a family affected with non-syndrome X-linked intellectual disability (NS-XLID) using whole exome sequencing (WES).</p><p><b>METHODS</b>Multiplex ligation-dependent probe amplification (MLPA) was applied to screen potential mutations of Fragile X syndrome (FXS). Whole exome sequencing (WES) and Sanger sequencing were screen for pathological mutations.</p><p><b>RESULTS</b>FXS was excluded by MLPA analysis. WES has discovered in the proband an ARX gene mutation c.88G>T, which was confirmed by Sanger sequencing. Combining his clinical phenotype with information from the OMIM database, it was inferred that the ARX mutation probably underlies the NS-XLID in the proband. The same mutation was found in his mother and two uncles but not in his father and sister.</p><p><b>CONCLUSION</b>WES is capable of revealing the mutation underlying NS-XLID and can facilitate genetic counseling for the affected families.</p>