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Biomedical subjects

A Superti-Furga

Publications and source records attributed to A Superti-Furga.

108 records · Page 6Linked to original sources
PubMed1989

Ehlers-Danlos syndrome type IV: a subset of patients distinguished by low serum levels of the amino-terminal propeptide of type III procollagen.

Serum levels of procollagen type III aminopropeptide (P-III-NP), a peptide released during conversion of type III procollagen to collagen, were abnormally low in six of 10 patients with Ehlers-Danlos syndrome (EDS) type IV (arterial-ecchymotic type) and low-normal in 4. The serum P-III-NP levels correlated with the amount of type III procollagen secreted by the patients' cultured fibroblasts. Serum P-III-NP determination is a simple test that identifies a major subgroup of patients with this life-threatening, dominantly inherited connective tissue disorder and may be especially helpful in making the diagnosis in children.

Adolescent↗
PubMed1989

Molecular defects of type III procollagen in Ehlers-Danlos syndrome type IV.

Fibroblasts from most patients with Ehlers-Danlos syndrome (EDS) type IV, a disorder characterized by fragility of skin, blood vessels, and internal organs, secrete reduced amounts of type III procollagen. In 7 of 8 cell strains analyzed, we found evidence of structural defects in half of the type III procollagen chains synthesized, such as deletions or bona fide amino acid substitutions, which cause delayed formation and destabilization of the collagen triple helix and, as a consequence, reduced secretion of the molecule. The data suggest that EDS type IV is often caused by heterozygosity for mutations at the COL3A1 locus, which affect the structure of type III procollagen. The triple-helical region of the molecule, like the homologous region of type I procollagen, appears to be particularly vulnerable.

DNA↗
PubMed1989

Clinical variability of osteogenesis imperfecta linked to COL1A2 and associated with a structural defect in the type I collagen molecule.

We report a family in which dominant osteogenesis imperfecta segregates with a COL1A2 haplotype and is associated with a structural defect in the helical region of the type I procollagen molecule. All affected subjects had short stature, dentinogenesis imperfecta, and myopia; however, great differences were observed in the number of fractures and in the degree of bone deformity. Identical biochemical changes were found in the type I collagen molecules synthesised by fibroblasts of subjects with severe or minimal bone fragility. These results confirm that mutations in the triple helical region of alpha 2(I) chains produce a milder phenotype than analogous mutations in the alpha 1(I) chains, but indicate that, in addition to defects in the type I collagen molecule, other factors may modulate the degree of bone involvement in osteogenesis imperfecta.

Adult↗
PubMed1988

Ehlers-Danlos syndrome type IV: a multi-exon deletion in one of the two COL3A1 alleles affecting structure, stability, and processing of type III procollagen.

We have studied a patient with severe, dominantly inherited Ehlers-Danlos syndrome type IV. The results indicate that this patient carries a deletion of 3.3 kilo-base pairs in the triple helical coding domain of one of the two alleles for the pro-alpha-chains of type III collagen (COL3A1). His cultured skin fibroblasts contain equal amounts of normal length mRNA and of mRNA shortened by approximately 600 bases, and synthesize both normal and shortened pro-alpha 1(III)-chains. In procollagen molecules containing one or more shortened chains, a triple helix is formed with a length of only about 780 amino acids. The mutant procollagen molecules have decreased thermal stability, are less efficiently secreted, and are not processed as their normal counterpart. The deletion in this family is the first mutation to be described in COL3A1.

Adult↗
PubMed1988

Impaired secretion of type III procollagen in Ehlers-Danlos syndrome type IV fibroblasts: correction of the defect by incubation at reduced temperature and demonstration of subtle alterations in the triple-helical region of the molecule.

The amount of type III procollagen secreted by fibroblasts from two patients with type IV Ehlers-Danlos syndrome is reduced to 25% and 20%, respectively, of that of control cells after incubation at 37 degrees C, but reverts to 70% and 110% when cells are incubated at 32 degrees C. The type III procollagen molecules secreted only at the lower temperature are of normal size but apparently contain different mutations which disrupt the triple-helical region and lower the thermal stability of the molecule. These data suggest that subtle mutations in the pro alpha 1(III)-chains produce Ehlers-Danlos syndrome type IV by disrupting the triple-helical region of the molecule, lowering its thermal stability, and thus impairing its secretion. At the lower temperature, stabilization of the defective molecules result in more efficient secretion. This approach may be useful for the characterization of other unstable collagens.

Cell Line↗
PubMed1988

Effects of the long-acting somatostatin analogue SMS 201-995 in an infant with intractable diarrhea.

The long-acting somatostatin analogue SMS 201-995 was administered to a six-month-old infant with intractable diarrhea after failure of conventional treatment. During eight weeks of treatment, the secretory component of the diarrhea was positively influenced with a reduction of daily stool weight and stool sodium concentration. Plasma levels of growth hormone were markedly, and levels of insulin, IGF I, gastrin, pancreatic polypeptide, VIP, and neurotensin moderately decreased. Linear growth was also inhibited. The patient unexpectedly died from fulminant colitis at a time, when the dosage had been reduced from 18 to 3.5 micrograms/kg/day. The relationship, if any, between therapy with SMS 201-995 and the colitis remained unclear. It is concluded that SMS 201-995 can be effective in reducing secretory diarrhea in infants. However, further studies are necessary to assess the safety of its administration in this age group.

Antidiarrheals↗
PubMedDate not supplied

Identification of fifteen novel mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene in European patients with severe hypophosphatasia.

Hypophosphatasia is an inherited disorder characterised by defective bone mineralisation and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. We report the characterisation of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 13 European families affected by perinatal, infantile or childhood hypophosphatasia. Eighteen distinct mutations were found, only three of which had been reported previously in North American and Japanese populations. Most of the 15 new mutations were missense mutations, but we also found two mutations affecting donor splice sites and a nonsense mutation. A missense mutation in the last codon of the putative signal peptide probably affects the final maturation of the protein. Despite extensive sequencing of the gene and its promotor region, only one mutation was identified in two cases, one of which was compatible with a possible dominant effect of certain mutations and the putative role of polymorphisms of the TNSALP gene. In 12 of the 13 tested families, genetic diagnosis was possible by characterisation of the mutations or by use of polymorphisms as genetic markers. Hypophosphatasia diagnosis was assigned in two families where clinical, laboratory and radiographic data were unclear and prenatal diagnosis was performed in one case. The results also show that severe hypophosphatasia is due to a very large spectrum of mutations in European populations with no prevalent mutation and that genetic diagnosis of the disease must be performed by extensive analysis of the gene.

Alkaline Phosphatase↗