Partial trisomy 15 and temporal lobe syndrome in a retarded girl without gross malformations.

A supernumerary small bisatellited chromosome was found in a girl with stunted growth and psychomotor retardation. The extra chromosome was identified as a deleted 15, del(15)(q21), with C-band positive heterochromatin and satellite-like appendages to the distal end of the long arm. This chromosome was the product of a translocation between a chromosome 15 and some other acrocentric chromosome, as shown by G-, C- and Q-banding and silver staining of the nucleolus organizer regions. The proposita had no gross phenotypic malformations. She had a small head, a high forehead, oblique palpebral fissures, bilateral enophthalmus, clinodactyly and simple dermatoglyphic patterns. She was autistic and suffered from epileptic seizures and expressive aphasia. The waking electroencephalogram revealed diffuse abnormalities; sleep recording showed focal spikes and sharp waves anteriorly on the left side. The pneumo-encephalogram showed microventriculy, an enlarged left temporal horn and some enlarged sulci in the right frontotemporal cortex. The prenatal influence of the chromosome anomaly is interpreted as being the primary cause of these disorders, neonatal asphyxia being a secondary contributing factor.