To the Editor.—The findings of Terplan and Cohen (Amer J Dis Child115:179 [Feb] 1968) are susceptible to an interpretation quite different from that which the authors give them.
Examination of the published karyotype makes it seem very probable that the chromosome which is alleged to be a supernumerary 18 is actually the Y, and that the so-called Y is the fifth in group G (21-22); this signifies trisomy G. Clinically, the child is described as having "questionable mongoloid facies," "epicanthal folds on both eyelids and an underdeveloped bridge of the nose," and "moderate widening of the first interdigital space on each foot." This is the full description. This does not constitute evidence for trisomy 18. In the absence of clinical findings, there is no justification for designating the extra chromosome as an 18. The authors point out that there is a paucity of anomalies, the child having