In Reply.—We thank Drs Guntheroth et al for their pertinent comments.
Although the term ASH accurately describes the condition in infants of diabetic mothers (IDMs), it indeed may be confused with the autosomaldominant progressive condition. As stated in our article: "... the conditions are completely unrelated. In ASH of the IDM, there is no histologic evidence of myocardial cellular disarray, the condition rarely causes any clinically significant left-ventricular outflow obstruction, and it spontaneously resolves within the first year of life" (reference 1 above). In the IDMs with septal thickening, we did not detect any Doppler evidence of left-ventricular outflow obstruction or any evidence of systolic anterior motion of the anterior mitral valve leaflet. A less alarming term such as disproportionately thickened septum could be used; however, we noted that this condition is not "a generalized increase in the thickness of both ventricles," but, as shown in the Figure, an exaggerated ventricular septal