Duchenne muscular dystrophy (DMD) is the most common and the most severe of the muscular dystrophies in man. It is inherited as an X-linked recessive trait and is characterized by ongoing necrosis of skeletal muscle fibres with regeneration and eventually fibrosis and fatty infiltration. Although the gene and gene product which are defective in DMD have recently been identified, the pathogenesis of the disease is still poorly understood. A myopathy has been described in the dog which has been shown to be inherited as an X-linked trait and which is therefore a potential model of the human disease. We have studied the phenotypic expression of the disease, canine X-linked muscular dystrophy (CXMD), and have examined the molecular relationship between it and DMD. We report here that dogs with CXMD faithfully mimic the phenotype of Duchenne muscular dystrophy and that they lack the Duchenne gene transcript and its protein product, dystrophin.

The growing study of leaving home in young adulthood in the United States has been hampered by data and measurement problems, which are producing a major theoretical confusion about the role of parental resources in influencing young adults' leaving home. Does high parental income retain young adults in the home or subsidize their leaving (and parental privacy)? This paper uses the 1984 panel of Survey of Income and Program Participation to clarify this issue, and shows that the effects of parental resources differ depending on the route out of the home under consideration (marriage or premarital residential independence). Effects change substantially over the nest-leaving ages, but relatively few differences are found between young men and young women.

The extent of mobility and changes in living arrangements associated with disability were studied using data from the 1984-86 Longitudinal Study of Aging. It was hypothesized that persons with significant limitations in their ability to perform normal daily activities (ADLs and IADLs) in 1984 would be more likely to move, more likely to be living with others in 1986, and more likely to have entered an institution between 1984 and 1986 than those without limitations. When only those variables that were measured in 1984 were used as predictors, this turned out to be true for institutionalization and for living with others in 1986. However, among those remaining in households, residential mobility showed little relationship to disability when other variables were controlled. When the change in disability between 1984 and 1986 was added to the prediction equation, there were strong relationships between changes in disability and both residential mobility and adjustment in living arrangement, suggesting that people respond quickly to significant changes in disability. However, because we cannot be sure that the changes in disability preceded the mobility or changes in living arrangements, we cannot claim to have established a causal link between these events.