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D L Rimoin

Publications and source records attributed to D L Rimoin.

At least 73 records · Page 4Linked to original sources
PubMed1995

Pseudoachondroplasia and multiple epiphyseal dysplasia due to mutations in the cartilage oligomeric matrix protein gene.

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) are dominantly inherited chondrodysplasias characterized by short stature and early-onset osteoarthrosis. The disease genes in families with PSACH and MED have been localized to an 800 kilobase interval on the short arm of chromosome 19. Recently the gene for cartilage oligomeric matrix protein (COMP) was localized to chromosome 19p13.1. In three patients with these diseases, we identified COMP mutations in a region of the gene that encodes a Ca++ binding motif. Our data demonstrate that PSACH and some forms of MED are allelic and suggest an essential role for Ca++ binding in COMP structure and function.

Achondroplasia↗
PubMed1995

Dominant mutations in the type II collagen gene, COL2A1, produce spondyloepimetaphyseal dysplasia, Strudwick type.

The chondrodysplasias are a heterogeneous group of disorders characterized by abnormal growth or development of cartilage. Current classification is based on mode of inheritance as well as clinical, histologic, and/or radiographic features. A clinical spectrum of chondrodysplasia phenotypes, ranging from mild to perinatal lethal, is due to defects in the gene for type II collagen, COL2A1. This spectrum includes Stickler syndrome, Kniest dysplasia, spondyloepiphyseal dysplasia congenita (SEDC), achondrogenesis type II, and hypochondrogenesis. Individuals affected with these disorders exhibit abnormalities of the growth plate, nucleus pulposus, and vitreous humor, which are tissues that contain type II collagen. The Strudwick type of spondyloepimetaphyseal dysplasia (SEMD) is characterized by disproportionate short stature, pectus carinatum, and scoliosis, as well as dappled metaphyses (which are not seen in SEDC). The phenotype was first described by Murdoch and Walker in 1969, and a series of 14 patients was later reported by Anderson et al. The observation of two affected sibs born to unaffected parents led to the classification of SEMD Strudwick as an autosomal recessive disorder. We now describe the biochemical characterization of defects in alpha 1(II) collagen in three unrelated individuals with SEMD Strudwick, each of which is due to heterozygosity for a unique mutation in COL2A1. Our data support the hypothesis that some cases, if not all cases, of this distinctive chondrodysplasia result from dominant mutations in COL2A1, thus expanding the clinical spectrum of phenotypes associated with this gene.

Adult↗
PubMed1995

A radiographic, morphologic, biochemical and molecular analysis of a case of achondrogenesis type II resulting from substitution for a glycine residue (Gly691-->Arg) in the type II collagen trimer.

The type II collagenopathies form a continuous spectrum of clinical severity, ranging from lethal achondrogenesis type II and hypochondrogenesis, through spondyloepiphyseal dysplasia, spondyloepimetaphyseal dysplasia and Kniest dysplasia to the Stickler syndrome and familial precocious osteoarthropathy at the mildest end of the spectrum. We have carried out a radiographic, morphologic, biochemical and molecular study in a case of achondrogenesis type II. Electron micrographs showed inclusion bodies of dilated rough endoplasmic reticulum in the chondrocytes and the presence of sparse collagen fibers in the cartilage matrix. Protein analysis of collagen from cartilage indicated posttranslational overmodification of the major cyanogen bromide peptides, and suggested a mutation near the carboxyl terminus of the type II collagen molecule. Analysis at the DNA level demonstrated that the phenotype was produced by a single base change (G-->C) that resulted in the substitution of glycine691 by arginine in the type II collagen triple helical domain. We confirm previous observations in three cases of hypochondrogenesis that glycine substitutions in the alpha 1(II) chain can result in a phenotype at the most severe end of the type II collagenopathy spectrum.

Abortion, Induced↗
PubMed1995

An RNA-splicing mutation (G+5IVS20) in the type II collagen gene (COL2A1) in a family with spondyloepiphyseal dysplasia congenita.

Defects in type II collagen have been demonstrated in a phenotypic continuum of chondrodysplasias that includes achondrogenesis II, hypochondrogenesis, spondyloepiphyseal dysplasia congenita (SEDC), Kniest dysplasia, and Stickler syndrome. We have determined that cartilage from a terminated fetus with an inherited form of SEDC contained both normal alpha 1(II) collagen chains and chains that lacked amino acids 256-273 of the triple-helical domain. PCR amplification of this region of COL2A1, from genomic DNA, yielded products of normal size, while amplification of cDNA yielded a normal sized species and a shorter fragment missing exon 20. Sequence analysis of genomic DNA from the fetus revealed a G-->T transversion at position +5 of intron 20; the affected father was also heterozygous for the mutation. Allele-specific PCR and heteroduplex analysis of a VNTR in COL2A1 independently confirmed the unaffected status of a fetus in a subsequent pregnancy. Thermodynamic calculations suggest that the mutation prevents normal splicing of exon 20 by interfering with binding of U1 small-nuclear RNA to pre-mRNA, thus leading to skipping of exon 20 in transcripts from the mutant allele. Electron micrographs of diseased cartilage showed intracellular inclusion bodies, which were stained by an antibody to alpha 1(II) procollagen. Our findings support the hypothesis that alpha-chain length alterations that preserve the Gly-X-Y repeat motif of the triple helix result in partial intracellular retention of alpha 1(II) procollagen and produce mild to moderate chondrodysplasia phenotypes.

Adult↗
PubMed1995

Genetic skeletal dysplasia in Thailand: the Siriraj experience.

Genetic skeletal dysplasias are a heterogeneous group of genetic disorders associated with abnormalities in the skeletal system frequently presenting with disproportionate short stature. There are over 100 distinct skeletal dysplasias which have been classified primarily on the basis of the clinical or radiographic characteristics. We have identified many genetic skeletal dysplasia disorders at Department of Pediatrics, Siriraj Hospital, Bangkok, Thailand. We have cases of achondroplasia, hypochondroplasia, pseudoachondroplasia, atelosteogenesis, pyknodysostosis, spondyloepiphyseal dysplasia (SED) congenita, spondylometaepiphyseal dysplasia (SMED), osteogenesis imperfecta type I, II and III, Ellis-van Creveld syndrome, cleidocranial dysostosis, thanatophoric dysplasia, rhizomelic chondrodysplasia punctata, trichorhinophalangeal syndrome, mucopolysaccharidosis I, II, IV and VI, mucolipidosis II, osteopetrosis, camptomelic dysplasia, metaphyseal dysplasia with spine involvement (Kozlowski type), Langer-Gideon syndrome and hypophosphatemic rickets. We have established a Genetic Skeletal Dysplasia Clinic at Siriraj Hospital since 1992, and see referrals from around the country. Genetic counseling is provided, including prenatal diagnosis and a multidisciplinary approach.

Bone Diseases, Developmental↗
PubMed1994

Desbuquois syndrome: clinical, radiographic, and morphologic characterization.

To further characterize the clinical, radiographic and chondro-osseous morphologic changes in the Desbuquois syndrome, 7 patients from three sibships are described. They all had prenatal onset severe rhizomelic and mesomelic shortness with marked joint laxity and marked micrognathia. Radiographic changes were distinct, consisting of a supernumerary ossification center between the proximal phalanx of the index finger and the second metacarpal, and variable thumb changes. The femoral necks showed enlargement of the lesser trochanter with metaphyseal breaking, producing a characteristic "monkey wrench" (Swedish key) appearance. Growth plate cartilage showed dilated cisterns of rough endoplasmic reticulum in reserve zone chondrocytes. Three of the 7 cases were diagnosed prenatally by second trimester ultrasound and one case by fetoscopy. This syndrome exhibits significant phenotypic variability and must be differentiated from the Catel-Manzke syndrome which exhibits similar radiographic changes in the hands.

Adolescent↗
PubMed1994

Microcephalic osteodysplastic dysplasia.

We present two patients with a distinct facial phenotype, short stature, brachydactyly, clubfoot deformities, cataracts, microcephaly, and normal intelligence. Similar radiographic abnormalities of the spine, long bones, hands, and feet were noted. These patients are similar to 2 males previously described by Saul and Wilson [1990: Am J Med Genet 35:388-393]. These 4 patients appear to have a unique skeletal dysplasia characterized by microcephaly, distinct facial phenotype, multisystem abnormalities, and short stature of postnatal onset.

Abnormalities, Multiple↗
PubMed1994

A large family with features of pseudoachondroplasia and multiple epiphyseal dysplasia: exclusion of seven candidate gene loci that encode proteins of the cartilage extracellular matrix.

We have identified a large family with a dominantly inherited chondrodysplasia characterized by a waddling gait, short limbs, and early onset osteoarthritis. The radiographic presentation resembles pseudoachondroplasia in childhood and multiple epiphyseal dysplasia in adults. Electron microscopic examination of cartilage reveals accumulation of material within the rough endoplasmic reticulum similar to that seen in pseudoachondroplasia and the Fairbank type of multiple epiphyseal dysplasia. By linkage analysis, we have excluded the genes for aggrecan, decorin, hexabrachion (tenascin), type II procollagen, the alpha 1 chain of type XI procollagen, the alpha 1 chain of type IX procollagen, and link protein, candidate genes that encode structural components of the cartilage extracellular matrix, as the disease locus for this disorder.

Abnormalities, Multiple↗
PubMed1994

Single-strand conformation polymorphism analysis of human decorin, biglycan and fibromodulin cDNAs.

The coding regions of the human decorin, biglycan and fibromodulin cDNAs have been examined utilizing the method of single-strand conformation polymorphism analysis. Analysis of total RNA from a group of eight human skin fibroblast cell lines did not detect any sequence variations in the decorin cDNA. In contrast, the analysis detected three sequence variations in the biglycan cDNA and one in the fibromodulin cDNA from the same group of cell lines. For the biglycan cDNA, one variation involved a position in the 5'-untranslated region, while the other two affected the wobble bases of triples encoding serine residues 10 and 143 of the mature core protein. For the fibromodulin cDNA, the variation involved the wobble position of the codon for glutamic acid residue 61 of the putative mature core protein. Single-strand conformation polymorphism analysis of these proteoglycan cDNAs was also applied to study patients exhibiting a variety of connective tissue pathologies, including chondrodysplasia punctata, Desbuquois syndrome, Dyggve-Melchior-Clausen syndrome, dyssegmental dysplasia, Ehlers-Danlos syndrome types I and III, Ellis van Creveld syndrome and thanatophoric dysplasia, though no additional sequence variations were detected.

Base Sequence↗
PubMed1994

A single amino acid substitution (G103D) in the type II collagen triple helix produces Kniest dysplasia.

Kniest dysplasia is a moderately severe chondrodysplasia phenotype that results from mutations in the gene for type II collagen, COL2A1. Characteristics of the disorder include a short trunk and extremities, mid-face hypoplasia, cleft palate, myopia, retinal detachment, and hearing loss. Recently, deletions of all or part of exon 12 have been identified in individuals with Kniest dysplasia, suggesting that mutations within this region of the protein may primarily result in the Kniest dysplasia phenotype. We used SSCP to analyze an amplified genomic DNA fragment containing exon 12 from seven individuals with Kniest dysplasia. An abnormality was identified in one patient. DNA sequence analysis demonstrated that the patient was heterozygous for a G to A transition that implied substitution of glycine103 of the triple helical domain by aspartate. The mutation was not observed in DNA from either of the clinically unaffected parents of the proband. Protein microsequencing demonstrated expression of the abnormal allele in cartilage. These data demonstrate that point mutations which result in single amino acid substitutions can produce Kniest dysplasia and further support the hypothesis that alteration of a domain, which includes the region encoded by exon 12, in the type II collagen protein leads to this disorder.

Amino Acid Sequence↗
PubMed1993

Hydrops-ectopic calcification-moth-eaten skeletal dysplasia (Greenberg dysplasia): prenatal diagnosis and further delineation of a rare genetic disorder.

An offspring of consanguineous parents of East-Indian origin was found prenatally to have hydrops fetalis, short limb dwarfism, polydactyly and chondro-osseous changes consistent with Greenberg hydrops-ectopic calcification-moth-eaten skeletal dysplasia (HEM) dysplasia. The radiological changes include platyspondyly with multiple extra ossification centers, extraneous calcification in the ribs, sternum, pelvis, and epiphysis, and moth-eaten long bones. The histopathological changes included chondrocytes with dilated rough endoplasmic reticulum and inclusion bodies with homogeneous material of intermediate electron density. These findings further delineate the spectrum of this rare autosomal recessive skeletal dysplasia.

Abnormalities, Multiple↗
PubMed1993

Hearing loss and temporal bone structure in achondroplasia.

Characteristic temporal bone changes have recently been defined by high resolution CT in nine patients with achondroplasia (Cobb et al., Am J Neuroradiol 9:1195, 1988). These included narrowing of the skull base and "towering" petrous ridges resulting in abnormal orientation of the inner and middle ear structures. In order to determine whether these morphologic changes are the cause of the hearing deficit in achondroplasia, audiometric studies and ENT evaluation were performed in eight of the nine patients. All had a history of frequent otitis media and four had experienced tympanic membrane tube insertion. Three patients had significant sensorineural hearing loss, two had conductive hearing loss and one patient had combined hearing loss. None of the temporal bone morphologic changes were found to be correlated with the degree of either sensorineural or conductive hearing loss. Fusion of the ossicular chain was not present in any of our cases. Appropriate treatment of frequent acute otitis media and early awareness of middle ear effusions and conductive hearing loss in children with achondroplasia may be of great importance in preventing permanent hearing loss.

Achondroplasia↗
PubMed1993

New epiphyseal stippling syndrome with osteoclastic hyperplasia.

We present a lethal skeletal dysplasia characterized radiographically by severe stippling of the lower spine and long bones and periosteal cloaking. In contrast to the normal morphology of the epiphyses and growth plates, the marrow was filled with loose fibrous tissue containing numerous large multinucleated osteoclasts which were associated with Howship's lacunae on the endosteal surface. We suggest the term "Pacman dysplasia" to describe this unusual histologic change that characterizes this new bone dysplasia.

Chondrodysplasia Punctata↗
PubMed1993

Spondylo-meta-epiphyseal dysplasia (SMED), short limb-hand type: a congenital familial skeletal dysplasia with distinctive features and histopathology.

We report on a "new" severe short-limb bone dysplasia which can be labeled descriptively a spondylo-meta-epiphyseal dysplasia. The 3 patients were born to 2 unrelated Sepharadic Jewish families and a Puerto Rican family. Clinical abnormalities include small stature with short limbs including short hands, a short nose with wide nasal bridge and wide nostrils, a long philtrum, ocular hypertelorism, retro/micrognathia, and a narrow chest. Radiological abnormalities include platyspondyly, short tubular bones with very abnormal metaphyses and epiphyses beyond early infancy, short ribs, and a typical evolution of bony changes over time. Chondroosseous morphology and ultrastructure document sparse matrix and degenerating chondrocytes surrounded by dense amorphous material in the 1 patient studied. Consanguinity is present in 1 family. In addition to the described patient, 2 other short-limb sibs, who did not survive infancy, were born into this family. Even in the absence of any photographic or radiologic documentation of these other 2 infants, autosomal recessive mode of inheritance seems probable.

Bone Diseases, Developmental↗
PubMed1993

Fetal akinesia/hypokinesia sequence: prenatal diagnosis and intra-familial variability.

Intrauterine fetal movement plays a key role in normal embryonic and fetal development (Moessinger, 1983). When movement is absent or decreased, abnormal development takes place which can be appreciated in newborns and/or fetuses with the fetal akinesia/hypokinesia sequence. This sequence is caused by a number of heterogeneous entities which result in decreased fetal movements by the action of intrinsic or extrinsic factors. Prenatal diagnosis of the akinesia/hypokinesia sequence may be possible during the second trimester through the use of real-time ultrasonographic evaluation of fetal movement. We report a family with three consecutive affected pregnancies in which the prenatal presentation of this sequence varied. Based on the phenotypic findings of the three affected fetuses, we believe that although they superficially resemble those features found in the New-Laxova syndrome, they are probably affected with a distinctly different lethal form of akinesia/hypokinesia transmitted in an autosomal recessive fashion.

Abnormalities, Multiple↗