Familial Turner syndrome.

Seven women in three generations of a family have been affected by Turner syndrome. Turner phenotype in this family is the result of deletion of the entire short arm of one X chromosome. The short arm deletion is transmitted by carriers of a balanced X-1 translocation. Autoradiographic findings showed that the deleted X chromosome was late labeling in those persons with Turner syndrome, whereas the normal X chromosome was late replicating in carriers of the balanced translocation. The results of Xga typing of erythrocytes suggest that the Xg locus is on the short arm of the X chromosome. Because of the clinical implications, we believe that families of persons with structural chromosomal abnormalities should be studied to exclude familial transmission.