Studies of the cranial base in 23 patients with cri-du-chat syndrome suggest a cranial developmental field involved in the condition

The purpose of the present study was to investigate the cranial base on pro file radiographs of patients with cri-du-chat syndrome and to relate the fi ndings to current knowledge of brain malformation in an attempt to localize the developmental field affected in cri-du chat syndrome. The material of profile radiographs of 23 patients was collected in Denmark in the 1970s. T wenty-two patients had terminal deletions of chromosome 5 (5p13.3, 5p14.1, 5p14.2, and 5p14.3), and one patient had an interstitial deletion. The cran ial base angle (n-s-ba) was in most cases reduced and in no cases increased compared to age-related standards for normal individuals. Malformations in the bony contours of the sells turcica and the clivus occurred in cri-du-c hat patients with terminal deletions. This specific cranial base region dev elops around the notochord at the location from where the rhombencephalic-d erived brainstem, pens, and cerebellum have developed dorsally, and from wh ere the neurons to the larynx have migrated ventrally. As the cranial base, the cerebellum and the larynx are involved in cri-du-chat syndrome, and at tention is drawn to a new developmental field which comprises the dorsum se llae, clivus, cerebellum, and larynx. This field seemingly originates from the same notochordal location. The study has demonstrated a cranial base ma lformation in cri-du-chat patients, which ought to be elucidated in future research and combined with neurological and chromosomal investigations. (C) 1999 Wiley Liss, Inc.