Schizophrenia is considered to be a heterogenous disorder. Different e
tiopathological mechanisms can be attributed to a similar clinical pic
ture as described in DSM-III-R criteria. We present a case of a young
man diagnosed on different occasions as schizophrenic with mild mental
retardation, Clinical examination revealed signs and symptoms most co
mpatible with the diagnosis of Lujan-Fryns syndrome, an X-linked menta
l retardation syndrome with marfanoid features, frequently associated
with psychotic or other psychiatric symptoms. In all patients with sym
ptoms of schizophrenia and mental retardation Lujan-Fryns syndrome sho
uld be considered in the differential diagnosis. (C) 1996 Wiley-Liss,
Inc.