To the Editor.— The letter of Miller et al ( 214 :2337, 1970) describes a young woman with some of the features of Turner's syndrome. The karyotype reproduced in the article is likely to mislead readers who are not familiar with chromosome morphology. The third pair of chromosomes in group A is mislabeled as is the sex chromosome pair (XX). The latter pair is actually number 3—arms and legs are about equal. The pair placed by the authors in the A3 position are C group chromosomes and the larger of the two might be an X. However, actual identification of the two Xs would require examination of other more favorable metaphase chromosome preparations. Barr body (or sex chromatin) studies should also include description of the size of the sex chromatin body, a smaller than normal one might be a lead toward recognizing a partial deletion of the short arm of an