The relationship between changed or erratic behavior of nine Ss with Prader-Willi syndrome (a disorder involving retardation, obesity, and hypotonia) and their ingestion of excess kcalories from sucrose was examined. Results showed that out of 162 test correlations performed, only eight were significant, the number expected by chance. (Author)

Physical, psychological, and cytogenic characteristics of individuals with the Fragile X syndrome are reviewed. Prospects for therapy with folic acid, prenatal diagnosis, phenotype of heterozygote for the marker X, and unresolved issues about the syndrome are discussed. (CL)

Six 4- to 37-year-old patients with tuberosis sclerosis (a chronic condition characterized by siezures, intercranial calcification, a reddish-yellow sebaceous glandular mass on the face, and frequent crises in early years), did not exhibit an elevation of the (alpha + beta) globulin fraction in their serum. (Author/MC)

The cases of two mentally retarded adult siblings with the classical features of Albright's osteodystrophy (a disease with characteristics such as short stature and abnormal sexual development) were reported. (Author/DB)

The article reviews information regarding genetic defects in the mucopolysaccharidoses (MPSs), which are hereditary diseases that result in deformities related to connective tissues (some types lead to progressive mental retardation). (Author/PHR)

Brain-injured (N=24), cultural-familially retarded (N=24), and nonretarded (N=28) adolescents and young adults were compared on a letter priming task requiring recognition of matched pairs. Response time in both retarded groups was considerably slower than in the nonretarded group, and effortful processing was also slower to develop. (JW)