[Molecular-genetic characteristics of the deleted region of chromosome 8q24.1 in Langer-Giedion and tricho-rhino-phalangeal type I syndromes]. / MOlekuliarno-geneticheskaia kharakteristika oblasti deletsii khromosomy 8q24.1 pri sindromakh Langer-Gidiona i trikho-rino-falangovom I tipa.

A molecular-genetic characterization of deletions in part of chromosome 8q24.1 was performed in patients with Langer-Giedion syndrome (six patients) and triho-rhino-phalangeal syndrome type I (three patients) by means of Southern blot hybridization analysis, restriction fragment length polymorphism and single-strand conformation polymorphism, analysis. Four families with multiple exostosis chondrodysplasia (MECD) also underwent the same analysis. Results of deletion mapping allowed determination of the probable region of localization of the proposed gene of MECD at D8S67 locus. By means of a polymorphic DNA probe obtained from the locus an additional hybridization signal was revealed only in patients with MECD. Other polymorphic DNA probes and microsatellite sequences confirmed the results of deletion mapping and detected haplotypes on the chromosomes with a mutation in the proposed MECD gene.

[Ultrastructure of skin fibroblasts in storage diseases (mucopolysaccharidosis types IV and VI)]. / Ul'trastruktura fibroblastov kozhi pri nekotorykh bolezniakh nakopleniia (mukopolisakharidozakh IV i VI tipov).

Ultrastructure of skin fibroblasts was studied in patients with mucopolysaccharidoses of types IV and VI and their relatives. In MPS VI and keratan-nonexcreting form of MPS IV the cytoplasm of fibroblasts contained numerous vacuoles with material of various electron density. The ultrastructure of cell did not differ from the norm in the keratan-excreting form of MPS IV. Skin fibroblasts from parents and siblings with MPS VI were found to contain a large number of residue bodies. The possible usage of ultrastructural data for early diagnosis of MPS and in medical genetic consultation of families of the patients with MPS is discussed.

[Morphological characteristics of lesions of the cartilaginous growth plate in several forms of osteochondrodysplasias]. / Morfologicheskie osobennosti porazheniia khriashchevoi rostkovoi plastinki pri nekotorykh formakh osteokhondrodisplazii.

The authors have carried out a search for morphological markers for diagnosing, differential diagnosis and medico-genetic consulting of 4 forms of osteochondrodysplasias. The cells and the intercellular substance of the cartilaginous graft plate from the upper flaring portion of the ileum of the patients were investigated. A common feature of most conditions were changes on the part of the granular endoplasmatic net, which points at a disturbance in the function of the synthesis apparatus and/or of the transport of the synthesized biopolymers. No morphological changes were revealed in the cartilaginous graft plate which were pathognomonic for spondyloepiphyseal dysplasia, achondroplasia and multiple exostosis chondrodysplasia. In one of the forms of pseudoachondroplasia (its severe dominant heritable variation) there were specific inclusions in the chondrocytes of the patients, which apparently were a morphological manifestation of disturbed assembly of proteoglycan aggregates which is the basis of the pathogenesis of pseudoachondroplasia. The possibility of using this morphological marker in the clinico-genetic classification of pseudoachondroplasia, in differential diagnosis of the disease in unclear cases as well as in medico-genetic consulting of the patients' families is discussed.

A single base mutation in the type II procollagen gene (COL2A1) that converts glycine alpha 1-247 to serine in a family with late-onset spondyloepiphyseal dysplasia.

A search for mutations in the gene for type II procollagen (COL2A1) was carried out in a family with late-onset spondyloepiphyseal dysplasia resulting in short sature, restricted mobility and severe pain in joints, deforming arthritis in the hips, and claudication. Analysis of the HindIII and VNTR polymorphisms at the COL2A1 gene in the family raised the possibility that the gene cosegregated with the disease. Screening for mutations in the COL2A1 gene using PCR-denaturing gradient get electrophoresis suggested a sequence variation in exon 19 of one allele of the COL2A1 gene in the proband. Direct sequencing of the PCR products for exon 19 revealed a single base mutation that converted the codon of -GGT- for glycine at alpha 1-247 to -AGT-, a codon for serine. The mutant that converted the present in all affected family members, but absent in nonaffected members and in a group of 50 unrelated healthy individuals. It was also absent in 20 unrelated patients with chondrodysplasia and 30 unrelated patients with early-onset osteoarthritis.

[Morphofunctional aspects of genetic analysis of osteogenesis imperfecta in cultured skin fibroblasts]. / Morfofunktsional'nye aspekty geneticheskogo analiza nesovershennogo osteogeneza v kul'ture kozhnykh fibroblastov.

Osteogenesis imperfecta (OI) is a disease with biochemical evidence of abnormality in collagen biosynthesis. We report here that expression of the OI phenotype extends to the level of dermal fibroblast morphology in vitro. Growth characteristics and morphology of control (n = 3) and 01 cell strains (n = 10) were compared. Our results show that (1) OI fibroblasts take longer time (16 days) than that with control cells (13 days) to reach stationary phase; (2) OI fibroblasts achieve a lower cell density (1.0 +/- 0.09) at stationary phase compared to control cells (1.47 +/- 0.1); p < 0.01; (3) cell shape (expressed as the width/length ratio) was also abnormal in OI cells: they have significantly increased ratios (p < 0.05) compared to control. These changes were associated with an increased level of fibronectin concentration and engorged cytoplasmic vesicles in dermal fibroblasts in vitro. We have reason to suspect that dysmorphology of fibroblasts may be related to aberrant collagen metabolism that leads to inadequacy of extracellular substratum, that in its turn hinders normal adhesion of cells as well as their spreading, morphology and fibronectin concentration.

A missense mutation of C1659 in the fibroblast growth factor receptor 3 gene in Russian patients with hypochondroplasia.

To carry out the genetic screening for the common mutation in the first tyrosine kinase domain (TK1) of the fibroblast growth factor receptor 3 gene (FGFR3) in a Russian population, a cohort of 16 patients with hypochondroplasia diagnosed previously were studied, among them twelve familial cases and four sporadic cases. The heterozygous N540K FGFR3 mutation was detected in 9 cases (56.3%) due to that C1659A substitution in 6 patients and C1659G substitution in 3 patients, respectively. The ratios of familial and sporadic cases among patients which carried FGFR3 mutation were similar. Seven (43.7%) patients, negative cases of N540K mutation, were all familial cases. Our results support evidence of similar frequency of common type N540K mutation of FGFR3 in Russian hypochondroplasia and of the genetic heterogeneity of hypochondroplasia, suggesting the need for further search for responsible molecular abnormalities for phenotypically similar hypochondroplasia patients negative for TK1 domain mutation in FGFR3, reported in hypochondroplasia.

[Pathogenetic aspects of studying clonal properties of bone marrow stromal cells in diseases of the osteoarticular system]. / Patogeneticheskie aspekty izucheniia klonal'nykh svoistv stromal'nykh kletok kostnogo mozga pri zabolevaniiakh kostno-sustavnogo apparata.

Properties of clonogenic stromal fibroblasts of bone marrow which are precursors of osteo- and chondrogenesis, of patients with different diseases of osteoarticular apparatus have been studied. Peculiarities of their reaction on growth-stimulating influence of nonstromal auto- and xenogeneic cells have been demonstrated. The possibilities of data application for studying of pathogenesis of hereditary osteochondrodysplasias as well as other groups of the skeleton affections are considered.