We report on an infant with the neonatal progeroid syndrome whose clinical course and autopsy findings indicate that this may be a heterogeneous phenotype. The infant had intrauterine growth retardation, absence of subcutaneous fat, and a wizened, aged face, all apparently characteristic of the condition, but also had congenital heart defects and urinary reflux not reported in previous cases. An elevated maternal serum alpha fetoprotein was noted at 16 weeks of gestation and late-onset growth retardation appeared after 31 weeks. Autopsy findings showed normal cerebral myelination, in contrast to findings of sudanophilic leukodystrophy in the one patient with the syndrome previously examined at autopsy. These findings suggest that the neonatal progeroid syndrome may be a phenotype and have more than one cause.