Investigation of the GSalpha gene in the diagnosis of fibrous dysplasia.

Fibrous dysplasia is a benign fibro-osseous disease of bone and its etiology has been previously established. Activating mutations in the gene that encodes the alpha subunit of stimulatory G protein (G(S)alpha) has been described in monostotic and polyostotic fibrous dysplasia and in the McCune-Albright syndrome. The present report describes a patient with monostotic fibrous dysplasia which diagnosis was confirmed by sequencing of the G(S)alpha gene, demonstrating a heterozygous missense mutation on codon 201 (201C --> T). Due to the high prevalence of G(S)alpha gene mutations in fibrous dysplasia in contrast to other benign and malignant fibrous-osseous lesions, mutational analysis are an additional and helpful parameter for the diagnosis of fibrous dysplasia in selected cases.