Proteus syndrome: A case report and review of the literature.

Proteus syndrome is a rare complex syndrome involving clinical presentation with atypical skeletal growth. Only a limited number of cases with this syndrome have been reported in the literature to date. We herein report the case of a Chinese male patient with Proteus syndrome and review the clinical and molecular characteristics of this disease. The patient was a 34-year-old man with clinical manifestations suggestive of the Proteus syndrome, including mosaic distribution of the lesions, sporadic occurrence, progressive course, disproportionate overgrowth of the legs, epidermal nevi, lipomas, venous malformations and characteristic facial phenotype. Genetic mosaicism, such as mutations involving the phosphoinositide 3 kinase-AKT pathway in the affected tissues, may be important causes of Proteus syndrome. In the present case, samples from the affected tissues were collected from the patient and were further analyzed using whole-exome sequencing. However, no mutation of the genes reportedly associated with Proteus syndrome was identified in the affected tissues. Proteus syndrome is a complex mosaic disorder with a number of variable characteristics. Although activating AKT1 mutations have been found to be associated with this disorder, the molecular etiology remains to be fully elucidated and diagnostic criteria must be established in the clinical setting.