Schinzel-Giedion syndrome: report of splenopancreatic fusion and proposed diagnostic criteria.

We report on the 46th patient with Schinzel-Giedion syndrome (SGS) and the first observation of splenopancreatic fusion in this syndrome. In the antenatal period, a male fetus was found to have bilateral hydronephrosis. Postnatally, in keeping with a diagnosis of SGS, there were large fontanelles, ocular hypertelorism, a wide, broad forehead, midface retraction, a short, upturned nose, macroglossia, and a short neck. Other anomalies included cardiac defects, widened and dense long bone cortices, cerebral ventriculomegaly, and abnormal fundi. Splenopancreatic fusion, usually encountered in trisomy 13, was found on autopsy. Schinzel-Giedion syndrome is likely a monogenic condition for which neither the heritability pattern nor pathogenesis has yet been determined. A clinical diagnosis may be made by identifying the facial phenotype, including prominent forehead, midface retraction, and short, upturned nose, plus one of either of the two other major distinguishing features: typical skeletal abnormalities or hydronephrosis. Typical skeletal anomalies include a sclerotic skull base, wide supraoccipital-exoccipital synchondrosis, increased cortical density or thickness, and broad ribs. Other highly supportive features include neuroepithelial tumors (found in 17%), hypertrichosis, and brain abnormalities. Severe developmental delay and poor survival are constant features in reported patients.