We report on three patients with MeCP2 mutation and male Rett phenotypes. Two brothers with T158M mutations and normal karyotype had a severe early onset encephalopathy, progressive microcephaly, severe feeding problems, breathing and sleep disturbances. They died at the ages of 1 year and 8 months, and 3 years and 1 month. This mutation has previously been reported in three males. The phenotypes show a strong resemblance, and might in fact represent a clinical-genetic entity of the T158M mutation within the complex of congenital encephalopathies in males with MeCP2 mutations. We also report a 3-year-old boy with a R294X mutation, normal karyotype, and a more protracted course. He was inactive and sucked poorly from start. The head growth decelerated from the age of 6 months and the feeding problems increased requiring gastrostomy. He had a rapid deterioration period at 2 years and lost sitting and hand grasping functions. He had prolonged periods with tremor and epileptic myoclonus, shifting tonus, and dystonic extension of the trunk and legs, bruxism, and irregular breathing. He was clinically stable with preserved visual and emotional contact function by the age of four years. None of the boys had dysmorphic features.