A patient defines the interstitial 1q deletion syndrome characterized by antithrombin III deficiency

A patient with microbrachycephaly, high forehead, long philtrum, thin upper lip, downturned corners of the mouth, low set ears with overlapping helix, fifth-finger clinodactyly, small hands and feet, bilateral transverse palm ar crease, low total finger ridge count, hypotonia, severe growth and psych omotor delay, mild hypoplasia of corpus callosum, and Arnold-Chiari type I malformation is reported. The karyotype showed 46, XY, del(1)(q23q31.2). Co agulation factor V (F5, 1q23) and coagulation factor XIII (F13B, 1q31-q32.1 ) levels were normal. As expected, antithrombin III (AT3, 1q23-q25.1) serum level and activity were half of normal. We performed a review of the liter ature on proximal and intermediate deletion 1q syndrome, and we hypothesize the existence of only one 1q interstitial deletion syndrome, clinically ch aracterized by ATIII deficiency. (C) 2001 Wiley-Liss, Inc.