[A clinical study of Proteus syndrome caused by a mosaic somatic mutation in AKT1 gene]

Objective: Proteus syndrome is a rare disease. The aim of the present study was to analyze the clinical characteristics and gene mutations of Proteus syndrome with a case report and relevant literature review. Methods: Clinical data of the patient with Proteus syndrome were collected in detail and biochemical measurements and radiological examinations were conducted. Tissues from phalanges with lesions were obtained to extract DNA, and Sanger sequencing of AKT1 gene was carried on. The pathogenic mutation was further tested in peripheral blood samples of the patient, his parents and 250 healthy volunteers. Orthopaedic surgery was performed on the affected limbs of the patient. Results: The patient was presented with progressive overgrowth of the right extremity, scoliosis, cerebral connective tissue nevus and lower extremity venous. A heterozygous mutation of AKT1 gene (c. 49G>A) was identified in DNA extracted from the affected bone tissue of the patient, but not be found in genomic DNA of peripheral blood samples from the patient, his parents and 250 healthy volunteers. Movement function of the affected limb improved significantly after the operations. Conclusions: The prominent features of Proteus syndrome are overgrowth of one extremity and cerebral connective tissue nevus. A mosaic somatic mutation of AKT1 gene is one of the pathogenic mutations for Proteus syndrome, and orthopedic surgery may be a good way to improve symptoms of the disease.