Progressive pseudorheumatoid dysplasia PPD is a rare autosomal recessive skeletal dysplasia caused by mutations in the Wnt1-inducible signaling pathway protein 3 WISP3 gene. Available literatures in PPD emphasized treatment strategy for polyarthritis, while few mentioned spinal deformity and related surgical intervention. Here, we present a Chinese man with PPD who underwent spinal surgery twice because of canal stenosis and related symptoms caused by the disease.
Whole-exon sequencing WES was performed to confirm diagnosis before the second surgery. A homozygous missense mutation c. Our study illustrated a surgical outcome of PPD and highlighted the significance of early diagnosis and individualized surgical strategy, and also verified the value of WES in the diagnosis of PPD.
Progressive pseudorheumatoid dysplasia PPD is an autosomal recessive disease characterized by spondyloepiphyseal dysplasia associated with progressive joint deformities, pain, stiffness, and swelling mainly in the spine and hip joints [ 1 ]. PPD is caused by mutation in the Wnt1-inducible signaling pathway protein 3 WISP3 gene, which consists of five exons and encodes a amino acid protein [ 2 ]. WISP3 belongs to the connective tissue growth factor CCN gene family, and the encoded protein plays an essential role in skeletal growth and cartilage homeostasis [ 3 ].
This disease is usually misdiagnosed as juvenile idiopathic arthritis or juvenile rheumatoid arthritis JRA , and patients can receive many years of unnecessary treatment before correct diagnosis [ 4 ]. Whole-exon sequencing WES is useful for identifying rare monogenic inherited diseases [ 5 ], and the reducing cost of WES has improved the feasibility of its clinical use [ 6 ].
In this study, we employed WES to explore the potential causative genes in a Chinese PPD patient who underwent spinal surgical treatment twice. The proband was a year-old male from Hebei province in the north of China. He is of Han ethnicity and was born to consanguineous parents. His family pedigree is shown in Fig. The proband was normally delivered after a full-term pregnancy, and birth weight and length were within normal ranges. Deformity of interphalangeal joints initially appeared in the fingers.
