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Biomedical subjects

D L Rimoin

Publications and source records attributed to D L Rimoin.

At least 19 recordsLinked to original sources
PubMed1992

Spondylometaphyseal dysplasia, Sedaghatian type.

In 1980 Sedaghatian described an Iranian infant who died shortly after birth. At autopsy, he was found to have subacute myocarditis, cortical necrosis of kidneys, and adrenal and pulmonary hemorrhage. His skeletal abnormalities included mild rhizomelic shortness of his limbs and platyspondylyl and "laciness" of the iliac wings. In 1987 Optiz et al. described another Iranian infant with a similar perinatal course and roentgenograms. This infant was born to first cousins, suggesting an autosomal recessive single gene defect. We report our findings of another infant with a lethal course.

Bone and Bones↗
PubMed1992

An amino acid substitution (Gly853-->Glu) in the collagen alpha 1(II) chain produces hypochondrogenesis.

The spondyloepiphyseal dysplasia subclassification of bone dysplasias includes achondrogenesis, hypochondrogenesis, and spondyloepiphyseal dysplasia congenita. The phenotypic expression of these disorders ranges from mild to perinatal lethal forms. We report the detection and partial characterization of a defect in type II collagen in a perinatal lethal form of hypochondrogenesis. Electrophoresis in sodium dodecyl sulfate-polyacrylamide of CB peptides (where CB represents cyanogen bromide) from type II collagen of the diseased cartilage showed a doublet band for peptide alpha 1(II)CB10 and evidence for post-translational overmodification of the major peptides (CB8, CB10, and CB11) seen as a retarded electrophoretic mobility. Peptide CB10 was digested by endoproteinase Asp-N; and on reverse-phase high pressure liquid chromatography, fragments of abnormal mobility were noted. Sequence analysis of a unique peptide D12 revealed a single amino acid substitution (Gly-->Glu) at position 853 of the triple helical domain. This was confirmed by sequence analysis of amplified COL2A1 cDNA, which revealed a single nucleotide substitution (GGA-->GAA) in 5 of 10 clones. Electron micrographs of the diseased cartilage showed a sparse extracellular matrix and chondrocytes containing dilated rough endoplasmic reticulum, which suggested impaired assembly and secretion of the mutant protein. This case further documents the molecular basis of the spondyloepiphyseal dysplasia spectrum of chondrodysplasias as mutations in COL2A1.

Amino Acid Sequence↗
PubMed1991

Deletion of 20p 11.23----pter with normal growth hormone-releasing hormone genes.

Using a molecular analysis of the DNA from a patient with a deletion of chromosome 20 [46,XX,del(20)(p 11.23)], we have excluded the growth hormone-releasing hormone (GHRH) gene from the region 20p11.23----pter. The patient had minor facial anomalies. Rieger eye anomaly, a congenital heart defect, severe failure to thrive, and a neurosecretory problem in growth hormone (GH) secretion. Since the GHRH gene was previously mapped to chromosome 20, we used molecular genetic methods to determine whether the growth abnormalities were due to the deletion of this gene. DNAs of the patient and 2 normal control subjects were analyzed by quantitative Southern blotting using a DNA probe for the GHRH gene and 2 reference DNA probes mapping to chromosome 21. The GHRH gene was found to be present in 2 copies in the patient. This indicates that the gene for GHRH maps to the region outside the patient's deletion, in 20p11.23----qter. Furthermore, our results suggest that genes other than GHRH on 20p are important for developmental steps leading to normal neurosecretory function of GH and may also be involved in generating Rieger eye anomaly. Finally, GH deficiency and Rieger eye anomaly should be sought in other patients with deletions of 20p.

Child↗
PubMed1991

Perinatal lethal hypophosphatasia; clinical, radiologic and morphologic findings.

Clinical, radiographic and morphologic analysis of nineteen cases of perinatal (lethal) hypophosphatasia was performed. Three families each had two affected offspring. All of the patients had lethal short limb dwarfism with very soft calvaria. Other clinical findings included polyhydramnios, blue sclerae and spurs in the mid-portion of the forearms and lower legs. Considerable variability was found in the skeletal radiographs. In addition to the well known radiographic features such as generalized decrease in the size of ossified bones with some bones not ossified at all, other changes observed included: 1) marked variability in the amount of bone ossification; 2) variability between patients as to which bones were most severely affected; 3) unusually dense, round, flattened, butterfly shaped; and sagittally clefted vertebral bodies; 4) variability in femoral shape including "chromosome" like, "campomelic" like, and shortening with or without metaphyseal cupping or irregularities; 5) osteochondral projections (Bowdler spurs) of the midshaft of the fibula and ulna. Recognition of the marked clinical and radiographic variability in this autosomal recessive lethal skeletal dysplasia is important for accurate genetic counseling and prenatal diagnosis.

Bone and Bones↗
PubMed1990

Rearrangement of chromosome 15 in the region q11.2----q12 in an individual with obesity syndrome and her normal mother.

Rearrangement of the proximal long arm of chromosome 15 have been found in most patients with the Prader-Willi syndrome (PWS) and in some with Angelman syndrome. We present an individual with syndromic obesity and her normal mother, who both have an abnormal chromosome 15. The proposita is a 26-year-old women with marked obesity, acanthosis, nigricans, short fingers, and severe cone degeneration of the retina. She has high plasma insulin levels, hypothyroidism, and an empty sella on CT scan. High-resolution chromosome banding demonstrated an increase in band 15q12. Further analysis showed the same abnormal 15 in her normal mother but not in her normal sister. This case and recent reports in the literature indicate that duplication of chromosome 15q in the PWS region may be associated with a syndrome of obesity, acanthosis nigricans, empty sella, and rodcore dystrophy as well as with a normal phenotype. Whether normal individuals with such a duplication carry increased risk of having offspring with an obesity syndrome is yet to be determined.

Acanthosis Nigricans↗
PubMed1990

Quantitative histology of cartilage vascular canals in the human rib. Findings in normal neonates and children and in achondrogenesis II-hypochondrogenesis.

Knowledge of the structure of cartilage vascular canals is important for a more thorough understanding of the development of cartilage and the growth plate in the human neonate and growing child. We have studied the costochondral junction of 6 normal neonates and 12 normal children (age 4 months-16 years) and utilised quantitative histomorphometry to define the percentage tissue area occupied by canals and the number of canals/mm2. Both percentage canal area and the number of canals/mm2 were significantly greater in newborn vs. older children (percentage area: 0.42 +/- 0.15 (mean +/- S.E.M.) vs. 0.08 +/- 0.04, P = 0.003; number/mm2: 0.2 +/- 0.09 vs. 0.04 +/- 0.02, P = 0.02). Eight newborn patients with achondrogenesis II-hypochondrogenesis were also studied. Both percentage canal area and number were significantly elevated above normal (percentage area: 5.22 +/- 1.01, P less than 0.001; number/mm2: 1.45 +/- 0.26, P less than 0.001). Results presented here demonstrate that: (i) quantitative differences in vascular canal area and numbers occur during development; (ii) 10-fold increases in vascular canal area and number are present in achondrogenesis II-hypochondrogenesis. Data from normal subjects will provide normative values against which vascular abnormalities in other skeletal dysplasias can be compared.

Aging↗
PubMed1990

Calcospherite (calcification nodule) size in the short rib polydactyly syndromes.

The short rib polydactyly syndromes (SRP) are lethal neonatal skeletal dysplasias with a narrow chest, short limbs, and other abnormalities. Type II (Majewski) short rib polydactyly can be distinguished from the Type I/III (Saldino-Noonan) type on the basis of radiographic and histologic changes. Our previous transmission electron microscopic studies suggested unusual patterns of cartilage calcification in these syndromes. We evaluate calcification in the present study using scanning electron microscopy and quantitative morphometry of calcification regions digested to expose calcospherite nodules (calcification nodules), distinctive morphologic structures which form during cartilage calcification. Mean calcospherite area of the Majewski Type II SRP (3.5 +/- 0.24 x 10(-6) mm2 (3) (mean +/- sem (n) did not differ from normal control means (3.1 +/- 0.5 x 10(-6) mm2, (3)). The mean area for Type I/III, however, was significantly larger than both the control and Type II means (8.9 +/- 1.16 x 10(-6) mm2 (7), p = .001). This difference in calcospherite size adds a further differentiating feature between these two dysplasias.

Calcinosis↗
PubMed1979

Duodenal-ulcer disease associated with elevated serum pepsinogen I: an inherited autosomal dominant disorder.

To delineate genetic factors involved in the pathogenesis of duodenal ulcer, serum pepsinogen I levels were determined by radioimmunoassay in two large kindreds with multiple members affected with duodenal ulcer. An elevated serum immunoreactive pepsinogen I concentration (greater than 100 ng per milliliter) segregated as an autosomal dominant trait in these families. Furthermore, 10 of 11 patients with clinical ulcer disease in these families had hyperpepsinogenemia. An elevated serum pepsinogen I concentration appears to be a subclinical marker of the ulcer diathesis in families with this autosomal dominant form of peptic-ulcer disease.

Duodenal Ulcer↗
PubMed1979

Further heterogeneity within lethal neonatal short-limbed dwarfism: the platyspondylic types.

Twelve infants, initially considered to have thanatophoric dysplasia, were studied by a combined radiographic-histochemical-biochemical approach. Three distinct forms of platyspondylic lethal neonatal short-limbed dwarfism could be distinguished: (1) Thanatophoric type, (2) Torrance type, and (3) San Diego type. The latter two disorders had similar radiographic abnormalities that were clearly different from those of typical thanatophoric dysplasia. All three disorders had clearly different condroosseous histopathologic abnormalities. Preliminary biochemical studies have revealed different electrophorectic abnormalities in solubilized type II collagen chains of cartilage in each of these three disorders.

Dwarfism↗
PubMed1979

Diastropic dwarfism: a histochemical and ultrastructural study of the endochondral growth plate.

Chondro-osseous tissue from five patients with diastropic dwarfism was studied by histologic, histochemical, and electron microscopic methods. The major abnormalities observed were: 1) irregular distribution of chondrocytes undergoing degeneration in the resting cartilage; 2) abnormal distribution of collagens in the resting cartilage; 3) a spectrum of fibrous matrix lesions in the resting cartilage which ranged from focal areas of aggregated collagen fibrils to large cystic lesions in which intracartilagenous ossification occurred; and 4) shortened, irregular cellular columns within the growth plate which were occasionally disrupted by matrix lesions extending from the resting cartilage. These alterations in chondro-osseous morphology have not been observed in any of the other skeletal dysplasias examined to date and appear to be pathognomonic for this disorder.

Adolescent↗
PubMed1979

Kniest dysplasia. A histochemical study of the growth plate.

Chondro-osseous tissue from four patients with the Kniest dysplasia was studied histochemically using a new plastic embedding technique. Extensive vacuolar changes were observed p--1 throughout the endochondral growth plate and adjacent resting cartilage. These changes occurred within the cartilage matrix and also in the lacunae of degenerating chrondrocytes. The septa of the lesions contained chondroitin sulfate, but little keratan sulfate or collagen. Resting cartilage not adjacent to the growth plate stained irregularly and showed few of the vacuolar lesions, and chondrocytes were enlarged and contained cytoplasic inclusions, but no vacuolar material. Thus, there appears to be a sequence of events initiated by cellular accumulation of a substance and progressing to cellular and matrix degeneration.

Adolescent↗
PubMed1979

Genetic heterogeneity of hyperpepsinogenemic I and normopepsinogenemic I duodenal ulcer disease.

In a search for a genetic marker of duodenal ulcer, we measured serum pepsinogen I levels in 168 ulcer patients and 151 of their clinically normal siblings. The ulcer patients tended to have either hyperpepsinogenemia I (pepsinogen I, greater than or equal to 100 ng/mL) or a normal level on a familial basis. Further evidence supporting this separation was the finding that the mean serum pepsinogen I level in the clinically normal siblings of the hyperpepsinogenemic patients was 91.2 ng/mL, significantly higher than the mean level (63.1 ng/mL) in the normal siblings of the normopepsinogenemic I patients. In the hyperpepsinogenemic I families the results of segregation analysis of an elevated pepsinogen I were consistent with autosomal-dominant inheritance of this trait. The genetic basis of normopepsinogenemic I duodenal ulcer was also shown by the familial aggregation of this disorder. These data provide direct evidence for genetic heterogeneity of duodenal ulcer disease.

ABO Blood-Group System↗