RESUMO
OBJECTIVE@#To carry out genetic testing for a patient with 45,X/46,XY mosaicism and autism spectrum disorder (ASD).@*METHODS@#Peripheral blood samples of the patient and his parents were collected for the extraction of genomic DNA. Trio-based whole exome sequencing and Sanger sequencing were carried out thereafter.@*RESULTS@#The proband and his father were found to harbor a heterozygous c.4781G>A (p.Arg1594Gln) variant of the CACNA1I gene. In addition, the proband was also found to harbor a de novo c.268C>T (p.Arg90Trp) missense variant of the MTRR gene. Based on guidelines of the American College of Medical Genetics and Genomics (ACMG), the c.4781G>A (p.Arg1594Gln) variant of the CACNA1I gene was predicted to be pathogenic (PVS1, PM1, PM2, PP3), while the c.268C>T (p.Arg90Trp) variant of the MTRR gene was predicted to be of uncertain significance.@*CONCLUSION@#Variants of the CACNA1I and MTRR genes, together with the chromosomal mosaicism, may have predisposed to the susceptibility to the ASD in this patient.