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D Rimoin

Publications and source records attributed to D Rimoin.

14 recordsLinked to original sources
PubMed1994

Expression, in cartilage, of a 7-amino-acid deletion in type II collagen from two unrelated individuals with Kniest dysplasia.

Kniest dysplasia is a heritable chondrodysplasia that severely affects skeletal growth. Recent evidence suggests that the etiology is based on mutations in COL2A1, the gene for collagen type II. We report the detection and partial characterization of an identical defect in type II collagen in two unrelated patients with Kniest dysplasia. Analysis of cyanogen bromide (CB)-digested cartilage samples from both probands by SDS-PAGE revealed an abnormal band for peptide alpha 1(II)CB12. The peptide was purified and digested with endoproteinase Asp-N. Fragments unique to the Kniest tissues were identified by reverse-phase high-pressure liquid chromatography and by sequence analysis. The results established a deletion of amino acids 102-108 of the alpha 1(II) triple-helical domain, which disrupted the (gly-X-Y)n repeat needed for helix formation. This was confirmed by sequence analysis of DNA amplified from both probands, revealing the molecular basis to be a single nucleotide mutation at a CpG dinucleotide (GCG-->GTG) in the codon for alanine 102. The mutation created a new splice donor site, which would account for the absence of the last seven amino acids from the 3' end of exon 12 in alpha 1(II)CB12. Light and electron micrographs of the probands' cartilage showed the perilacunar foamy matrix ("Swiss cheese") characteristic of Kniest dysplasia and chondrocytes containing dilated rough endoplasmic reticulum, which earlier studies had shown were filled with type II procollagen. These two cases strengthen the concept that Kniest dysplasia is based on mutations of COL2A1 and belongs within the broad spectrum of chondrodysplasias caused by type II collagenopathies.

Adult↗
PubMed1993

New form of spondyloepimetaphyseal dysplasia (SEMD) in Jewish family of Iraqi origin.

We report a distinct type of spondyloepimetaphyseal dysplasia seen in 2 sibs and their second cousin, characterized by early onset severe short stature, small chest, and distended abdomen. They had short neck, severe lumbar lordosis, and marked genu varum due to fibular overgrowth and joint laxity. Radiographically, the patients had platyspondyly, initially noted during the first years of life, with central hypoplasia of the vertebral bodies. At a later age, the vertebrae appear squared with mild interpedicular narrowing. The long bone changes, which at early age resemble those seen in achondroplasia, later include general metaphyseal irregularities and significant epiphyseal ossification delay. These patients present a previously undescribed form of spondyloepimetaphyseal dysplasia, most probably transmitted as an autosomal recessive tract.

Child↗
PubMed1989

Identification of the molecular defect in a family with spondyloepiphyseal dysplasia.

Spondyloepiphyseal dysplasias (SED) are a heterogeneous group of inherited disorders characterized by disproportionate short stature and pleiotropic involvement of the skeletal and ocular systems. Evidence has suggested that SED may result from structural defects in type II collagen. To confirm the validity of this hypothesis, the structure of the "candidate" type II collagen gene (COL2A1) has been directly examined in a relatively large SED family. Coarse scanning of the gene by Southern blot hybridization identified an abnormal restriction pattern in one of the affected members of the kindred. Analysis of selected genomic fragments, amplified by the polymerase chain reaction, precisely localized the molecular defect and demonstrated that all affected family members carried the same heterozygous single-exon deletion. As a consequence of the mutation, nearly 90 percent of the assembled type II collagen homotrimers are expected to contain one or more procollagen subunits harboring an interstitial deletion of 36 amino acids in the triple helical domain.

Amino Acid Sequence↗
PubMed1988

Kniest dysplasia is characterized by an apparent abnormal processing of the C-propeptide of type II cartilage collagen resulting in imperfect fibril assembly.

Epiphyseal and growth plate cartilages from four cases of Kniest dysplasia have been studied. In each case collagen fibril organization appeared abnormal by electron microscopy compared with age-matched normal cartilages: fibrils were much thinner, of irregular shape and did not exhibit the characteristic banding pattern. This was associated with the absence (compared with normal cartilage) of the C-propeptide of type II collagen (chondrocalcin) from the extracellular matrix of epiphyseal cartilages, although it was detected (as in normal cartilages) in the lower hypertrophic zone of the growth plate in association with calcifying cartilage. The C-propeptide was abnormally concentrated in intracellular vacuolar sites in Kniest cartilages and its total content was reduced in all cases but not in all cartilages. Moreover, it was not a part of the procollagen molecule. In contrast, type II collagen alpha-chain size was normal, indicating the formation of a triple helix. Also type II collagen content was normal and it was present in extracellular sites and only occasionally detected intracellularly. These observations suggest that the defect in Kniest dysplasia may result from the secretion of type II procollagen lacking the C-propeptide and abnormal fibril formation, and that the C-propeptide is normally required for fibril formation.

Calcium-Binding Proteins↗
PubMed1987

The Weissenbacher-Zweymüller phenotype in the neonatal period as an expression in the continuum of manifestations of the hereditary arthro-ophthalmopathies.

The authors report the case of a female infant who presented with bilateral congenital glaucoma and myopia diagnosed at six weeks. Her facies was flat with a very low nasal bridge and a vascular nevus covering the glabellar area, micrognathia and high arched palate. The limbs appeared shorter proximally and a radiologic skeletal survey revealed dumbbell shaped long bones, flattened acetabular roofs, posterior defects in the vertebral bodies in the thoracic region, platyspondyly. Seen in follow-up at nine weeks, 14 months and 24 months, after several goniotomies which successfully controlled her intraocular pressure, she presented with high myopia, moderate hypotonia and hyperextensible joints. The midfacial hypoplasia persisted, but the skeletal X-rays showed that the long bones seem to acquire a more elongated appearance. Her mental and motor development, although five to nine months delayed, reflected regular progress. The clinical findings in this patient suggest that she belongs in the heterogeneous category of ophthalmo-arthropathies described by Weissenbacher and Zweymüller and which is thought to be the neonatal expression of the Stickler syndrome. The need for early recognition of this syndrome and a better grasp of the natural history of these disorders are emphasized in order to support the hypothesis of a continuum of manifestations of the hereditary arthro-ophthalmopathies.

Child Development↗
PubMed1986

A new category of lethal short-limbed dwarfism.

We describe a first cousin marriage between Asians which resulted in 13 pregnancies; 4 of the offspring were normal, 5 were stillborn dwarves, 3 pregnancies resulted in miscarriage, and one was terminated for dwarfism detected prenatally. The radiology and histology are unique and the pedigree suggests autosomal recessive inheritance.

Consanguinity↗
PubMed1984

Prenatal diagnosis of asphyxiating thoracic dysplasia.

A fetus at risk for asphyxiating thoracic dysplasia was studied with ultrasound examination at 16, 18, and 23 weeks of pregnancy. Definite shortness of fetal femora was observed. Radiographic and histologic examinations after pregnancy termination confirmed the diagnosis. Asphyxiating thoracic dysplasia appears to be one of an increasing number of skeletal dysplasias that can be diagnosed prenatally with ultrasound.

Asphyxia Neonatorum↗
PubMed1984

Isolated growth hormone deficiency: immunocytochemistry.

Light and electron microscopic immunocytochemistry of the pituitary gland of a patient with documented isolated GH deficiency revealed parenchyma rich in GH positive cells. Immunoprecipitate was localized consistently over membrane-enclosed secretory granules whose features were characteristic of those in normal somatotrophs. No profiles of exocytosis of the contents of the secretory granules were observed. These observations demonstrate that the type I recessive form of isolated GH deficiency may be associated with apparently normal appearing somatotrophs which contain immunoreactive GH.

Aged↗
PubMed1981

Diastrophic dysplasia: the death of a variant.

Diastrophic dysplasia is a distinct autosomal recessive disorder originally described in 1960. Since that time, a number of patients with similar but less severe involvement have been diagnosed as having a "diastrophic variant" disorder. This study reviews the radiological features of classic diastrophic dysplasia and compares them with the radiological findings in 26 patients with the diastrophic variant disorder. It is concluded that there is a wide variability in the phenotypic expression of diastrophic dysplasia even within sibships, and that cases of diastrophic variant disorder are actually mild forms of diastrophic dysplasia.

Adolescent↗
PubMed1976

Heterogeneity in the campomelic syndromes. Long-and short-bone varieties.

Analysis of 9 cases of bilateral bent limbs (campomelia) and dwarfism, as well as a review of the literature, indicate that campomelic syndrome appears to be a well-defined distinct disorder which the authors call long-limbed campomelic syndrome. Other neonates with congenital bent-limbed dwarfism can be classified as having short-limbed campomelic syndrome, and among these at least two distinct forms have been delineated--the craniosynostotic and the normocephalic form. Congenital bent bones also occur in a variety of generalized disorders of ossification that must be distinguished from these well-defined types of campomelic dwarfism.

Abnormalities, Multiple↗