Kazimierz Kozlowski

Identification of signal peptide domain SOST mutations in autosomal dominant craniodiaphyseal dysplasia.

Sclerosteosis and Van Buchem disease are related recessive sclerosing bone dysplasias caused by alterations in the SOST gene. We tested the hypothesis that craniodiaphyseal dysplasia (CDD) (MIM 122860), an extremely rare sclerosing bone dysplasia resulting facial distortion referred to as “leontiasis ossea”, could also be caused by SOST mutations. We discovered mutations c.61G>A (Val21Met) and c.61G>T (Val21Leu) two children with CDD. As these mutations are located in the secretion signal of the SOST gene, we tested their effect on secretion by transfecting the mutant constructs into 293E cells. Intriguingly, these mutations greatly reduced the secretion of SOST. We conclude that CDD, the most severe form of sclerotic bone disease, is part of a spectrum of disease caused by mutations in SOST. Unlike the other SOST-related conditions, sclerosteosis and Van Buchem disease that are inherited as recessive traits seem to be caused by a dominant negative mechanism.

Atelosteogenesis syndromes: a review, with comments on their pathogenesis

Abstract The clinical, radiographic, and morphological findings in 25 cases of atelosteogenesis and boomerang dysplasia have been reviewed. The review confirms the nosologic grouping of atelosteogenesis type I with boomerang dysplasia and the clinical and radiographic overlap of features between atel- osteogenesis I and atelosteogene- sis II (synonymous with De la Chapelle dysplasia) and a group of patients with atelosteogenesis type III. A common pathogenesis is suggested for atelosteogenesis type I and boomerang dysplasia. A marked excess of male fetuses with boomerang dysplasia was observed. Atelosteogenesis type II shows distinctive chondro-osseous histopathology with a major disturbance in cartilage matrix macromolecules. An overlap of phenotypic, radiographic, morphological, and cartilage histochemical features with those observed in diastrophic dysplasia and achondrogenesis type IB suggests that atelosteogenesis type II has common pathogenetic features with disorders of sulfation of connective tissue matrix macro- molecules.

Czech dysplasia metatarsal type: another type II collagen disorder

Czech dysplasia metatarsal type is an autosomal-dominant disorder characterized by an early-onset, progressive spondyloarthropathy with normal stature. Shortness of third and/or fourth toes is a frequently observed clinical feature. Similarities between individuals with this dysplasia and patients with an R275C mutation in the COL2A1 gene, prompted us to analyze the COL2A1 gene in the original families reported with Czech dysplasia. Targeted sequencing of exon 13 of the COL2A1 gene was performed, followed by sequencing of the remaining exons in case the R275C mutation was not identified. We identified the R275C substitution in two of the original patients reported with Czech dysplasia and three additional patients. All affected individuals had a similar phenotype characterized by normal height, spondyloarthropathy, short postaxial toes and absence of ocular and orofacial anomalies. The R275C mutation was excluded in a third patient reported with Czech dysplasia. However, the identification of the Y1391C mutation in this patient with disproportionate short stature made the diagnosis of spondyloperipheral dysplasia (SPD) more probable. The Y1391C mutation is located in the C-propeptide of the procollagen chain and has been reported before in a patient with the Torrance type of lethal platyspondylic skeletal dysplasia (PLSD-T). Our observation of the same Y1391C mutation in an additional unrelated patient with SPD further supports the evidence that PLSD-T and SPD represent a phenotypic continuum. The R275C mutation in the COL2A1 gene causes a specific type II collagen disorder that was recently delineated as Czech dysplasia.

Du Pan syndrome phenotype caused by heterozygous pathogenic mutations in CDMP1 gene.

Du Pan syndrome is a rare acromesomelic dysplasia with characteristic clinical and radiographic findings. It is inherited as an autosomal recessive trait. Almost all the patients reported have been from Muslim countries. We report on a female and her child with Du Pan syndrome from a Caucasian, Polish family. Three new heterozygous mutations clustered on one allele of the CDMP1 gene were identified in the affected individuals resulting in the first familial case with dominant Du Pan syndrome. A possible synergistic effect of the cis‐acting mutations located in the active domain of the mature CDMP1 protein is likely to be responsible for the clinical expression of the disorder.

Acampomelic campomelic dysplasia with SOX9 mutation

Acampomelic campomelic dysplasia is a rare clinical variant of the more commonly encountered campomelic dysplasia (CMD1), characterized by absence of long bone curvature (acampomelia). We present a patient with acampomelic CMD1 with a de novo SOX9 missense mutation and report his clinical course to age one year, thereby contributing to genotype-phenotype correlation in CMD1. 2000.

Stüve-Wiedemann dysplasia in a 3 1/2-year-old boy

Stüve-Wiedemann osteochondrodysplasia is a rare disorder with distinct clinical and diagnostic radiographic findings. The condition is classified as a bent-bone dysplasia with early, lethal outcome. We report on a boy with Stüve-Wiedemann syndrome who is well and alive at the age of 3 1/2 years.

Novel amino acid substitution in the Y-position of collagen type II causes spondyloepimetaphyseal dysplasia congenita†

We report on monozygotic twins with short stature and severe spondyloepimetaphyseal dysplasia congenita (SEMDC) from the Polish population. Phenotype of the twin girls resembles spondyloepiphyseal dysplasia congenita Spranger–Wiedemann (SEDC‐SW), but shortening of the stature is more severe and the cranioface is normal. The distinctive radiographic features, in spite of similarity to SEDC‐SW, indicate different spinal and, notably, severe metaphyseal involvement. Molecular analysis of the COL2A1 gene revealed an A to G transition at nucleotide +79 of exon 41 that converted the codon for arginine at amino acid 792 to a codon for glycine (Arg792Gly). The twins were heterozygous for the mutation and neither parent had this change. The Arg792Gly substitution is located at the Y‐position of Gly‐X‐Y triplet, and it is likely that this substitution decreased the thermal stability of the triple helix and may affect fibril growth by replacement of an arginine residue, which is important for a conformation of the triple helix.

Tumors of Vascular Origin

Hemangiomas of bone are infrequent, about 1.2% of all primary bone tumors. In children, they are even more rare, though they do occur. Bone hemangioma is a benign lesion composed of newly formed blood vessels, capillaries or cavernous blood spaces filled with blood; it leads to a local loss of bone tissue, forming an osteolysis. In skeletal hemangiomatosis, multiple foci are observed throughout the skeleton. This lesion is probably a local hamartoma, rather than a true tumor growth, and therefore should be classified as a dysontogenetic tumor.

Cyclic bisphosphonate therapy in osteogenesis imperfecta type V

Abstract:  The clinical and radiographic features and management of a young person with recently delineated Osteogenesis Imperfecta Type V is described. A female aged 9 years presented with a history of multiple fractures since 3 years of age and bilateral dislocation of the elbows from infancy. She was commenced on a low dose frequent regimen of cyclic intravenous pamidronate, which resulted in progressive improvement in bone density, reduced fracture frequency and remission of symptoms of osteoporosis.

Dominantly inherited progressive pseudorheumatoid dysplasia with hypoplastic toes

ObjectiveTo present four related patients with progressive pseudorheumatoid dysplasia (PPsRD) each with distinctive history, unique phenotype and some peculiar radiographic findings.Results and conclusionsThe history was characterised by weather-dependent articular pain. The unique phenotypic features were hypoplasia/dysplasia of one or two toes. Peculiar radiographic findings were hypoplasia of the 3rd and 4th metatarsals, platyspondyly with rectangular shape of the lumbar spinal canal, progressive narrowing of the joint spaces and early synovial chondromatosis. Finally, the condition was inherited as a dominant trait. This constellation of abnormalities constitutes a distinct form of PPsRD. PPsRD must be differentiated from other bone dysplasias, specifically spondyloepiphyseal dysplasias, autosomal dominant spondylarthropathy, juvenile rheumatoid arthritis and osteoarthritis.