Abstract
Loss-of-function mutations of MECP2 are known to cause Rett syndrome, which is characterized by mental retardation and stereotyped hand movements in females. Recently, it has been revealed that in males, the duplication of Xq28 including MECP2 caused mental retardation. Here, we present 2 cases of boys with MECP2 duplication syndrome. Patient 1, an 18-year-old boy, showed severe psychomotor retardation in infancy. Epilepsy developed at the age of 4 years and was medically intractable. Callosotomy performed at the age of 13 years resulted in transient improvement. Patient 2, a 16-year-old boy, showed psychomotor retardation along with epilepsy and recurrent respiratory infections since early childhood. The findings of physical examination and laboratory tests were not specific. Array-comparative genomic hybridization of the X chromosome revealed that patients 1 and 2 had duplication of Xq28 including MECP2 in the 0.5Mb and 0.6Mb regions, respectively. Most of the patients with MECP2 duplication show not only mental retardation but also intractable epilepsy. Therefore, MECP2 duplication must be suspected when a male patient presents with symptoms of mental retardation, intractable epilepsy, and recurrent infection.
