Mesial temporal lobe abnormalities in a family with 15q26qter trisomy.

BACKGROUND

The association of chromosomal imbalances and neurologic abnormalities is well known.

OBJECTIVE

To describe a family with 2 brothers presenting with 15q trisomy due to a maternal equilibrated translocation involving chromosomes 12 and 15.

DESIGN, SETTING, AND PATIENTS: Among patients with epilepsy followed up in our hospital, we identified 2 brothers with epilepsy and mental retardation who presented dysmorphic features. Detailed clinical, electroencephalographic, and magnetic resonance imaging investigation was performed. In addition, we collected blood samples for karyotyping.

RESULTS

Clinical findings included minor dysmorphic features, mental retardation, abnormal behavior, and secondary generalized epilepsy. Electroencephalography showed left temporal slow waves in the older brother and background abnormality associated with generalized and multifocal epileptiform discharges in the other. Their magnetic resonance images showed mesial temporal lobe malformation, including the hippocampus and parahippocampal and fusiform gyri, with abnormal shape and axis.

CONCLUSIONS

To our knowledge, this is the first report of mesial temporal lobe malformation associated with chromosomal abnormalities. Our finding may contribute to the understanding of the genetic mechanisms involved in central nervous system malformations, especially in the mesial temporal lobe structures.