November 8 Highlights

Abstract

Zanni et al. analyzed the oligophrenin 1 gene ( OPHN1 ) in male patients with mental retardation with (17 patients) or without (196 patients) known cerebellar anomalies. The authors identified four novel OPHN1 mutations associated with distinguishing clinical and neuroimaging features. Of particular interest is the presence of cerebellar vermis and hemisphere hypoplasia. see page 1364 The editorial by Higgins and Topaloglu notes that besides raising issues whether individuals with OPHN1 gene mutations have syndromic-X-linked mental retardation, Zanni et al. identify a problem that plagues neurologists and neurogeneticists in the clinic. What is the correct diagnostic approach when presented with a child with X-linked mental retardation? Obtaining an MRI of the brain is a good start but if a cerebellar anomaly exists, the algorithm becomes complicated. A detailed knowledge of neuroimaging, genetics, and molecular neurobiology will raise many questions but not as many as how to decide whether the patient has a syndrome. A good beginning is to arrive at the clinicoradiologic diagnosis of X-linked oligophrenic vermian dysgenesis by identifying X-linked transmission of mental retardation in the family pedigree and analyzing the MRI for specific cerebellar …