Expression in fibroblast culture of the satellited-X chromosome associated with familial sex-linked mental retardation.

The satellited-X chromosome previously shown in lymphocyte culture to be associated with certain types of sex-linked mental retardation has, for the first time, been demonstrated in cultured skin fibroblasts and lymphocytes from two affected males and an obligate carrier female. These findings provide a basis for reliable diagnosis of female carriers and for the development of prenatal diagnosis.