Acrodysostosis is an uncommon skeletal dysplasia associated with nasal hypoplasia, midface deficiency, severe
brachydactyly, and varying degrees of
hearing loss and
mental retardation. Previous publications have suggested that it may be difficult to distinguish acrodystostosis from
pseudohypoparathyroidism on clinical grounds, but
acrodysostosis does appear to have distinct clinical and radiologic findings.
Spinal stenosis is an underappreciated risk in
acrodysostosis, despite the reported loss of normal caudal widening of the lumbar interpediculate distance on AP spine radiographs in the original report of this disorder by Robinow et al., with confirmation of these radiographic findings by Butler et al. We report two sporadic cases of
acrodysostosis, one of which required decompressive
laminectomy for symptomatic
spinal stenosis, and review 11 cases of
acrodysostosis from 9 families that were submitted to the International Skeletal Dysplasia Registry. The objective of this report is to determine the frequency and severity of
spinal stenosis in patients with
acrodysostosis and to summarize the clinical and radiographic findings of
acrodysostosis in an effort to distinguish
acrodysostosis clearly from
pseudohypoparathyroidism. The pattern of
brachydactyly differs between these two conditions, and varying degrees of
spinal stenosis are characteristic of
acrodysostosis. Both our index patients with
acrodysostosis had normal bioactivity of the alpha subunit of the Gs
protein, therefore indicating that
acrodysostosis has a different pathogenesis from
pseudohypoparathyroidism. Furthermore, single-strand confirmational polymorphism (SSCP) analysis failed to demonstrate any confirmational alterations in the coding exons of the Gs alpha gene. These radiographic and laboratory findings substantiate that
acrodysostosis is clinically different from
pseudohypoparathyroidism and that it is necessary to follow patients with
acrodysostosis for signs of
spinal stenosis.