Ambiguous Genitalia in the Russell-Silver Syndrome

Sir.—The review of the Russell-Silver syndrome by Marks and Bergeson¹ was timely, as well as noteworthy, for its emphasis on ambiguous genitalia. They concluded that their proband was "the third Silver-Russell syndrome child with ambiguous genitalia," and cited two previous cases. The first of these, described by Tulinius et al,² had 45,X/46,XY mosaicism that could have accounted for the ambiguous genitalia on its own. The second case³ was not karyotyped. Although the chromosomes in Marks and Bergeson's own case were normal male (46,XY), the other two cases left open to question whether ambiguous genitalia was more than coincidental to the 148 patients reviewed. That it was not mere coincidence was suggested by the demonstration that 22 of 52 male patients had cryptorchidism and 12 had hypospadias.¹ In order to further the notion that ambiguous genitalia may be a legitimate component of the Russell-Silver