RESUMEN
OBJECTIVE@#To provide genetic testing for two brothers with mental retardation and epilepsy.@*METHODS@#Array comparative genomic hybridization (aCGH) was used to detect copy number variations in the two patients, their parents and maternal grandparents. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was utilized to delineate the deleted region in the pedigree.@*RESULTS@#A 138 kb deletion in 15q11.2 region was detected by aCGH in both patients, which encompassed part of the UBE3A gene. MS-MLPA has narrowed down the region to exons 8 to 14 of the UBE3A gene. The same deletion was also found in their mother and grandfather.@*CONCLUSION@#The pathogenesis of this rare form of recurrent Angelman syndrome may be attributed to the partial deletion of maternal UBE3A gene.