Progressive pseudorheumatoid arthritis of childhood (PPAC) and normal adult height

Gait Alterations in Two Young Siblings with Progressive Pseudorheumatoid Dysplasia

Progressive pseudorheumatoid dysplasia (PPRD) is an autosomal recessive inherited skeletal dysplasia characterized by progressive non-inflammatory arthropathy affecting primarily the articular cartilage. Currently, little is known about the functional musculoskeletal aspects of these patients. In particular, an abnormal gait pattern has been described, without a clear hypothesis of the underlying causes in terms of muscular activity. This study presents the case of two siblings, 4 and 9 years old, a boy and a girl, respectively, suffering from PPRD at different stages of the disease. In addition to the clinical assessment, an instrumental gait analysis was performed. Swelling of the interphalangeal finger joints and fatigue were present in both cases. Gait abnormalities consisted of a relevant reduction in the ankle plantarflexion in the terminal phase of the gait cycle, associated with reduced gastrocnemius EMG activity and increased activity of the tibialis anterior, resulting in overloading at the initial peak of ground reaction forces. Gait anomalies observed were similar in both siblings with PPRD, although at different ages, and confirm walking patterns previously described in the literature. The calf muscle strength deficit and reduced activity during the stance phase of gait present in these two siblings indicate the typical absence of the propulsive phase. A stomping gait pattern, with the foot striking the ground hard on each step, was originally described. Further neurophysiological investigations are required to determine the origin of muscle weakness.

Progressive pseudorheumatoid dysplasia: a report of three cases and a review of radiographic and magnetic resonance imaging findings

Progressive pseudorheumatoid dysplasia (PPD) is a rare disorder of postnatal skeletal and cartilage development that often presents with similar clinical findings to juvenile idiopathic arthritis. Patients with PPD display findings of progressive cartilage loss and secondary osteoarthritis over serial imaging studies and have an absence of elevation of inflammatory markers. Awareness of the imaging features of PPD on radiographs and magnetic resonance imaging (MRI) may be important for early diagnosis and surveillance of the disease.

Progressive pseudorheumatoid dysplasia: a rare childhood disease

Progressive pseudorheumatoid dysplasia (PPRD) is a genetic bone disorder characterised by the progressive degeneration of articular cartilage that leads to pain, stiffness and joint enlargement. As PPRD is a rare disease, available literature is mainly represented by single case reports and only a few larger case series. Our aim is to review the literature concerning clinical, laboratory and radiological features of PPRD. PPRD is due to a mutation in Wnt1-inducible signalling protein 3 (WISP3) gene, which encodes a signalling factor involved in cartilage homeostasis. The disease onset in childhood and skeletal changes progresses over time leading to significant disability. PPRD is a rare condition that should be suspected if a child develops symmetrical polyarticular involvement without systemic inflammation, knobbly interphalangeal joints of the hands, and gait abnormalities. A full skeletal survey, or at least a lateral radiograph of the spine, can direct towards a correct diagnosis that can be confirmed molecularly. More than 70 WISP3 mutations have so far been reported. Genetic testing should start with the study of genomic DNA extracted from blood leucocytes, but intronic mutations in WISP3 causing splicing aberrations can only be detected by analysing WISP3 mRNA, which can be extracted from cultured skin fibroblasts. A skin biopsy is, therefore, indicated in patients with typical PPRD findings and negative mutation screening of genomic DNA.

A homozygous recurring mutation in WISP3 causing progressive pseudorheumatoid arthropathy

WISP3 is a member of the CCN (for CTGF, CYR61, and NOV) gene family, which encodes cysteine-rich secreted proteins with roles in cell growth and differentiation. Mutations in the WISP3 gene are associated with the autosomal recessive skeletal disorder, also known as progressive pseudorheumatoid arthropathy of childhood (PPAC). We diagnosed three siblings from a non-consanguineous family with PPAC. The patients were asymptomatic in early childhood. Signs and symptoms of disease that include progressive joint stiffness, swelling of the finger joints, and osteopenia, and slow linear growth developed between 2 and 8 years of age. PCR amplification and direct sequencing of the WISP3 gene revealed a homozygous mutation at nucleotide 156 of the WISP3 gene, resulting in a Cys52-to-ter substitution. This mutation has previously been reported in French, Italian, and Arab families. Interestingly, the C52X mutation was found to be associated with a c.248G-->A (G83E) variation, suggesting the existence of a founder effect. By contrast, the presence of the same aberration in three different ethnic groups could imply that this particular site is prone to mutation. Basal fasting concentrations of growth hormone, insulin-like growth factor-1, and insulin-like growth factor binding protein-3, as well as glucose and insulin levels revealed no aberrations. In conclusion, consideration of this rare disease that causes significant morbidity with short stature, osteopenia and arthritic complaints would prevent unnecessary examinations and treatment attempts. Testing for this specific mutation in suspected cases could provide a rapid and definitive diagnosis.

Molecular study ofWISP3 in nine families originating from the Middle-East and presenting with progressive pseudorheumatoid dysplasia: Identification of two novel mutations, and description of a founder effect

Progressive pseudorheumatoid dysplasia (PPD) is a rare autosomal recessive syndrome characterized by the presence of spondyloepiphyseal dysplasia associated with pain, stiffness, and swelling of multiple joints, osteoporosis, and the absence of destructive bone changes. The disorder is caused by mutations of the WISP3 gene located on chromosome 6q22. We hereby report the molecular study of the WISP3 gene in nine unrelated consanguineous families originating from the Middle-East: three from Lebanon, five from Syria, and one from Palestinian Bedouin descent, all affected with PPD. Five different sequence variations were identified in the WISP3 gene, two of them being new mutations: the c.589G --> C transversion at codon 197, responsible for a splicing defect (A197fsX201); and the c.536_537delGT deletion (C179fsX), both in exon 3. In all other families, the affected patients were homozygous for a previously described nonsense mutation, namely c.156C --> A (C52X). Interestingly, in the latter families, the C52X mutation was always found associated with a novel c.248G --> A (G83E) variation, suggesting the existence of a founder effect.

Skeletal dysplasias and the osteoarthritic phenotype

In contrast to late-onset osteoarthritis (OA), the appearance of precocious OA has historically been recognized as a particularly aggressive form of the disorder that is frequently inherited as a Mendelian trait. In general, precocious OA appears as a consequence of many skeletal dysplasias, which, although individually rare, comprise a sizable population of patients when viewed in toto. In these patients the disease is often rapidly progressive and includes features of articular and extra-articular involvement that are not typical of classic OA. The molecular pathology of the chondro-osseous disorders has been the focus of intense study in recent years, with the promise of providing insight into skeletal development and homeostasis, as well as the aetiology and pathogenesis of degenerative joint disease.

Inflammatory arthritis in children with osteochondrodysplasias

Osteochondrodysplasias are a heterogeneous group of genetic skeletal dysplasias. Patients with these diseases commonly develop an early degenerative arthritis or osteoarthritis. Occasional observations of inflammatory arthritis have been made in this population but such observations are based on clinical grounds alone without confirmatory imaging studies. Four patients followed up in a paediatric rheumatology clinic with three different skeletal dysplasias, who had both clinical and radiological evidence of an inflammatory arthritis and coexistent degenerative arthritis, are described.

Mutations in the CCN gene family member WISP3 cause progressive pseudorheumatoid dysplasia

Members of the CCN (for CTGF, cyr61/cef10, nov) gene family encode cysteine-rich secreted proteins with roles in cell growth and differentiation. Cell-specific and tissue-specific differences in the expression and function of different CCN family members suggest they have non-redundant roles. Using a positional-candidate approach, we found that mutations in the CCN family member WISP3 are associated with the autosomal recessive skeletal disorder progressive pseudorheumatoid dysplasia (PPD; MIM 208230). PPD is an autosomal recessive disorder that may be initially misdiagnosed as juvenile rheumatoid arthritis. Its population incidence has been estimated at 1 per million in the United Kingdom, but it is likely to be higher in the Middle East and Gulf States. Affected individuals are asymptomatic in early childhood. Signs and symptoms of disease typically develop between three and eight years of age. Clinically and radiographically, patients experience continued cartilage loss and destructive bone changes as they age, in several instances necessitating joint replacement surgery by the third decade of life. Extraskeletal manifestations have not been reported in PPD. Cartilage appears to be the primary affected tissue, and in one patient, a biopsy of the iliac crest revealed abnormal nests of chondrocytes and loss of normal cell columnar organization in growth zones. We have identified nine different WISP3 mutations in unrelated, affected individuals, indicating that the gene is essential for normal post-natal skeletal growth and cartilage homeostasis.

Fine mapping of progressive pseudorheumatoid dysplasia: a tool for heterozygote identification

Progressive pseudorheumatoid dysplasia is a skeletal genetic disorder affecting primarily the articular cartilage, causing joint stiffness and leading to a crippling status. More than two-thirds of the reported patients belong to Arab and Mediterranean populations. The disease locus has been mapped to chromosome 6q22 in a region of 12.9 cM using a Jordanian family. We examined two additional families, one Jordanian and one Palestinian, to test for homogeneity of the disorder and the presence of a common haplotype, to fine map the disorder, and to use all the information to derive a tool for heterozygote identification. The two families showed linkage to the same previously reported locus, thus suggesting homogeneity, but they did not share a common haplotype. They also provided information that refined the genetic region for the disease locus to 2.1 cM with three microsatellite markers. The absence of a common haplotype indicates that no common ancestor mutations were inherited by our patients. Genotyping for the three-marker haplotype showed that it can be used as a heterozygote identification tool.

Progressive pseudorheumatoid dysplasia: report of a family and review

Progressive pseudorheumatoid dysplasia is an inherited skeletal dysplasia with radiographic changes notably in the spine, similar to spondyloepiphyseal dysplasia tarda. There is also articular cartilage involvement which gives it some clinical resemblance to rheumatoid arthritis. We report here on six subjects from one inbred family from Jordan. Based on previously published reports and this one, we review the clinical and radiological features and discuss the genetics and differential diagnosis of the disorder. We suggest the addition of the word "spondyloepiphyseal" to the name adopted by the International Working Group on Constitutional Diseases of Bone, to become "progressive pseudorheumatoid spondyloepiphyseal dysplasia". We also speculate on candidate genes for this disorder.