Endocrine Significance of Short Metacarpals

Observations on 2594 outpatients indicate that shortness of the fourth metacarpals relative to the third and especially relative to the fifth (metacarpal sign) is of frequent occurrence in patients with gonadal dysgenesis having either female or male sex chromatin. Moreover, in males (Klinefelter's syndrome excluded), this metacarpal sign occurs much more frequently in the presence of some gonadal anomaly than when the gonads are normal. Among 105 males exhibiting the metacarpal sign and 136 others exhibiting only the borderline condition, all of those from whom buccal smears were taken were found to have male sex chromatin. In all 5 males with female sex chromatin, there was no metacarpal sign. On the basis of limited data, it appears that the metacarpal sign, when found in more than one generation of the same family, is without significance as far as gonadal development in any generation is concerned. However, when it is found in only one generation, it is frequently associated with gonadal aberration. The converse also is true. Patients having the metacarpal sign usually have delayed skeletal development. Though an occasional one is taller than average, the mean height is appreciably less than the average expected height based on the skeletal age. The deviations from average in the relative lengths of metacarpals which result in the metacarpal sign, occur both more frequently and to a greater extent in the left hand than in the right, but do not appear to be the result of hand dominance.