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Biomedical subjects

A Superti-Furga

Publications and source records attributed to A Superti-Furga.

At least 73 records · Page 4Linked to original sources

Bone marrow transplantation in cartilage-hair hypoplasia: correction of the immunodeficiency but not of the chondrodysplasia.

UNLABELLED: We diagnosed cartilage-hair hypoplasia (CHH) in a female child with prenatal-onset short stature, metaphyseal chondrodysplasia, and severe combined immunodeficiency leading to recurrent, severe respiratory tract infections. The patient required several hospital admissions during her 1st year of life and failed to thrive in spite of antimicrobial therapy and hypercaloric nutrition. Bone marrow transplantation (BMT) from an HLA-identical sister was performed at age 16 months after conditioning with busulphan and cyclophosphamide, using 9 x 10(8) nucleated bone marrow cells/kg body weight. Graft-versus-host disease prophylaxis consisted of cyclosporine and methotrexate. The post-transplantation period was uneventful. She developed full and sustained chimerism as demonstrated by DNA analysis of granulocytes and mononucleated cells on days 44, 69 and 455 post BMT. Cellular immunity was completely reconstituted at 4 months, humoral immunity at 15 months post BMT. The patient is alive and well 24 months post BMT without medication, but the radiological osseous changes persist, and longitudinal growth remains markedly below the 10th percentile for CHH standards; her height at age 3 years 4 months is 66 cm. CONCLUSION: In this patient with unusually severe CHH, bone-marrow transplantation has fully corrected the immune deficiency but has had no influence on the course of the chondrodysplasia.

Bone Marrow Transplantation↗

Phenotypic and genotypic overlap between atelosteogenesis type 2 and diastrophic dysplasia.

Mutations in the diastrophic dysplasia sulfate transporter gene DTDST have been associated with a family of chondrodysplasias that comprises, in order of increasing severity, diastrophic dysplasia (DTD), atelosteogenesis type 2 (AO2), and achondrogenesis type 1B (ACG1B). To learn more about the molecular basis of DTDST chondrodysplasias and about genotype-phenotype correlations, we studied fibroblast cultures of three new patients: one with AO-2, one with DTD, and one with an intermediate phenotype (AO2/DTD). Reduced incorporation of inorganic sulfate into macromolecules was found in all three. Each of the three patients was found to be heterozygous for a c862t transition predicting a R279W substitution in the third extracellular loop of DTDST. In two patients (DTD and AO2/DTD), no other structural mutation was found, but polymerase chain reaction amplification and single-strand conformation polymorphism analysis of fibroblast cDNA showed reduced mRNA levels of the wild-type DTDST allele: these two patients may be compound heterozygotes for the "Finnish" mutation (as yet uncharacterized at the DNA level), which causes reduced expression of DTDST. The third patient (with AO2) had the R279W mutation compounded with a novel mutation, the deletion of cytosine 418 (delta c418), predicting a frameshift with premature termination. Also the delta c418 allele was underrepresented in the cDNA, in accordance with previous observations that premature stop codons reduce mRNA levels. The presence of the DTDST R279W mutation in a total of 11 patients with AO2 or DTD emphasizes the overlap between these conditions. This mutation has not been found so far in 8 analyzed ACG1B patients, suggesting that it allows some residual activity of the sulfate transporter.

Anion Transport Proteins↗

Clinical course, early diagnosis, treatment, and prevention of disease in glutaryl-CoA dehydrogenase deficiency.

BACKGROUND: Glutaryl-CoA dehydrogenase deficiency (GDD) is a recessively inherited neurometabolic disorder associated with encephalopathic crises and severe extrapyramidal symptoms. Treatment regimens including glucose and electrolyte infusions during acute illnesses, oral carnitine supplementation and/or a low-protein or lysine-restricted diet have been recommended, but their efficacy has been documented only on an anecdotal basis. SUBJECTS AND METHODS: We conducted a retrospective analysis of 57 patients with proven GDD-relating appearance and severity of neurological disease to age and clinical status at diagnosis, glutaric acid levels in body fluids, and different treatment regimens. RESULTS: Thirty-six patients were diagnosed after the onset of neurological disease (symptomatic group), twenty-one before (presymptomatic group). Carnitine levels were found to be reduced in all patients at diagnosis. In the symptomatic group, macrocephaly had been present around birth and was followed by rapid postnatal head growth in 70% of the children. The patients often showed symptoms such as hypotonia, irritability, and jitteriness followed by an acute encephalopathic crisis occurring on average at 12 months of age. Common neuroimaging findings included frontotemporal atrophy, subependymal pseudocysts, delayed myelination, basal ganglia atrophy, chronic subdural effusions and hematomas. In four patients the latter two findings were initially misinterpreted as resulting from child abuse. Other important misdiagnoses in older siblings who were affected and went undiagnosed include postencephalitic cerebral palsy, dystonic cerebral palsy and sudden infant death syndrome. Metabolic treatment did not convincingly improve the neurological disease, although it may have prevented further deterioration. Symptomatic treatment with baclofen or benzodiazepines was effective in reducing muscle spasms. Children in the presymptomatic group were diagnosed because of familiarity for the disease (n = 13), macrocephaly and/or additional minor neurological signs in infancy (n = 6), or acute encephalopathy, which was fully reversible after prompt treatment (n = 2). After diagnosis, all children were treated with oral carnitine, fluid infusion during intercurrent illnesses and, in addition, a diet was started in 13 of the 21 children. All 21 children except one (born prematurely at 31 weeks) have continued to develop normally up to now. Mean age at report is 6.3 years with a range from 6 months to 14.8 years. In older patients, the neuroradiological changes, present in infancy as in the symptomatic patients, became less prominent and in one girl disappeared. CONCLUSIONS: In presymptomatic children with GDD, the onset of neurological disease can be prevented by vigorous treatment of catabolic crises during illnesses together with carnitine supplementation. The importance of dietary therapy remains unclear and needs further evaluation. The potential treatability of GDD calls for increased attention to early presenting signs in order to recognize the disorder and to initiate treatment before the onset of irreversible neurological disease.

Adolescent↗

Ehlers-Danlos syndrome type IV caused by Gly400Glu, Gly595Cys and Gly1003Asp substitutions in collagen III: clinical features, biochemical screening, and molecular confirmation.

Three patients with Ehlers-Danlos syndrome type IV (EDS IV) and biochemical evidence of structural defects in collagen III were investigated for mutations within the collagen III gene (COL3A1). Single strand conformation polymorphism analysis of alpha 1 (III) cDNA indicated the presence of different heterozygous sequence changes in each of the patients. Nucleotide sequencing revealed mutations leading to the substitution of glycine 400 with glutamic acid, glycine 595 with cysteine, and glycine 1003 with aspartic acid. EDS IV is a life-threatening disorder which, as the clinical histories of our patients and their families show, still often escapes diagnosis. Biochemical and molecular studies can clarify the diagnosis and help provide appropriate management and counselling.

Adult↗

The deletion of six amino acids at the C-terminus of the alpha 1 (II) chain causes overmodification of type II and type XI collagen: further evidence for the association between small deletions in COL2A1 and Kniest dysplasia.

We have identified an 18 bp deletion in exon 49 of the type II procollagen gene (COL2A1) in a patient with Kniest dysplasia. The deletion is located at the very C-terminus of the helical domain and removes two of three Gly-Pro-Pro triplets at positions 1007-1012, which are thought to be involved in helix formation and stability. Morphological investigation of an iliac crest biopsy showed large inclusions in the endoplasmic reticulum of chondrocytes, reflecting impaired secretion of type II collagen. Electrophoretic analysis of collagens extracted from cartilage or synthesised by cultured chondrocytes showed that type II and also type XI procollagen molecules containing mutant alpha 1 (II) chains showed post-translational overmodification. These observations provide further evidence for the general association of Kniest dysplasia with small deletions in the helical domain of type II collagen.

Amino Acid Sequence↗

Atelosteogenesis type II is caused by mutations in the diastrophic dysplasia sulfate-transporter gene (DTDST): evidence for a phenotypic series involving three chondrodysplasias.

Atelosteogenesis type II (AO II) is a neonatally lethal chondrodysplasia whose clinical and histological characteristics resemble those of another chondrodysplasia, the much less severe diastrophic dysplasia (DTD). The similarity suggests a shared pathogenesis involving lesions in the same biochemical pathway and perhaps the same gene. DTD is caused by mutations in the recently identified diastrophic dysplasia sulfate-transporter gene (DTDST). Here, we report that AOII patients also have DTDST mutations, which lead to defective uptake of inorganic sulfate and insufficient sulfation of macromolecules by patient mesenchymal cells in vitro. Together with our recent observation that a third even more severe chondrodysplasia, achondrogenesis type IB, is also caused by mutations in DTDST, these results demonstrate a phenotypic series of three chondrodysplasias of increasing severity caused by lesions in a single sulfate-transporter gene. The severity of the phenotype appears to be correlated with the predicted effect of the mutations on the residual activity of the DTDST protein.

Anion Transport Proteins↗

Osteoporosis-pseudoglioma syndrome, a disorder affecting skeletal strength and vision, is assigned to chromosome region 11q12-13.

Osteoporosis-pseudoglioma syndrome (OPS) is an autosomal recessive disorder characterized by severe juvenile-onset osteoporosis and congenital or juvenile-onset blindness. The pathogenic mechanism is not known. Clinical, biochemical, and microscopic analyses suggest that OPS may be a disorder of matrix homeostasis rather than a disorder of matrix structure. Consequently, identification of the OPS gene and its protein product could provide insights regarding common osteoporotic conditions, such as postmenopausal and senile osteoporosis. As a first step toward determining the cause of OPS, we utilized a combination of traditional linkage analysis and homozygosity mapping to assign the OPS locus to chromosome region 11q12-13. Mapping was accomplished by analyzing 16 DNA samples (seven affected individuals) from three different consanguineous kindreds. Studies in 10 additional families narrowed the candidate region, supported locus homogeneity, and did not detect founder effects. The OPS locus maps to a 13-cM interval between D11S1298 and D11S971 and most likely lies in a 3-cM region between GSTP1 and D11S1296. At present, no strong candidate genes colocalize with OPS.

Alleles↗

Gaucher disease: four families with previously undescribed mutations.

We describe four families with patients with type I Gaucher disease exhibiting previously undescribed mutations of the glucocerebrosidase gene. We found Cherokee Indian woman to have a G-->C substitution in cDNA nucleotide 354, predicting a lysine-->aspargine substitution in amino acid 79 of the processed protein. In a Greek family, we found an allele with a C-->T substitution in nucleotide 475 giving rise to an arginine-->tryptophan substitution at amino acid 120. In another non-Jewish European patient, we identified a C-->T substitution in nucleotide 1223, predicting a threonine-->methionine mutation in amino acid 369. We found two non-Jewish European children to have a C-->T mutation at nucleotide 1357, predicting termination at codon 414. Although siblings carry the same two glucocerebrosidase mutations, in these families as in others we noted considerable differences in severity of clinical manifestations. Finding the reason for these differences is an important goal in the study of Gaucher disease.

Adult↗

A glycine 375-to-cysteine substitution in the transmembrane domain of the fibroblast growth factor receptor-3 in a newborn with achondroplasia.

Achondroplasia, the most common form of chondrodysplasia, has been associated with mutations in the gene of the fibroblast growth factor receptor-3 (FGFR-3) on chromosome 4p. All 39 achondroplasia alleles studied so far carried point mutations which caused the same amino acid exchange, a substitution of glycine by arginine at position 380 (G380R) in the transmembrane domain of the receptor. We report on a newborn with achondroplasia who does not carry a G380R mutation but has a mutation causing substitution of a nearby glycine with a cysteine (G375C). This observation indicates allelic heterogeneity and confirms the role of mutations in the transmembrane domain of FGFR-3 in the pathogenesis of achondroplasia.

Achondroplasia↗

Phenotype of the Williams-Beuren syndrome associated with hemizygosity at the elastin locus.

UNLABELLED: To correlate presence or absence of a 7q11 microdeletion with the clinical picture of the Williams-Beuren syndrome (WBS), we investigated 29 patients with a clinical diagnosis of WBS or WBS-like features, aged 1-30 years, using molecular analysis and/or fluorescent in situ hybridization (FISH). Deletions at 7q11 were found in 75% of the patients (22 out of 29). Nine deletions occurred on a paternal, and ten on a maternal chromosome; three deletions were demonstrated by FISH only, and parental origin could thus not be determined. All deletion patients aged between 2 years and puberty displayed a distinct pattern of facial features (including periorbital fullness, short nose with flat bridge, wide mouth, and full lips and cheeks), the characteristic outgoing social behaviour, as well as moderate growth and mental retardation. Two-thirds (15 out of 22) had a cardiovascular malformation, but only one third (7 of 22) had supravalvular aortic stenosis (SVAS). A stellate iris pattern was also present in one-third of the patients only. In the four adult patients with 7q11 deletions, there was prominence of the lower lip whereas fullness of cheeks and periorbital tissue was not seen. CONCLUSION: This study confirms that WBS has a unique clinical picture which can be diagnosed clinically, but also shows that the relative frequency of individual features may have been overemphasized in the past, and that a minority of patients may exist who are clinically indistinguishable from WBS but who appear to have no deletion at 7q11.

Abnormalities, Multiple↗

Somatosensory evoked potentials with high cortical amplitudes: clinical data in 31 children.

Between 1989 and 1993, somatosensory evoked potentials (SEP) were recorded as part of the diagnostic work-up in 282 children with different neurologic disorders. In thirty-one children with N20/P25/N35 amplitudes were enhanced compared to our control group (highest amplitude 14.1 microV). Four children had amplitudes > 40 microV ("giant"), fifteen between 20-39.9 microV ("elevated") and twelve between 14-19.9 microV ("borderline"). Enhanced cortical SEPs were seen in all patients with neuronal ceroid lipofuscinosis (5 late-infantile NCL > 20 microV, 1 juvenile NCL 14.7 microV). In addition, five of six NCL children showed bilaterally prolonged cervico-cortical conduction times, otherwise only seen in a 4-month-old child following hypoxia. "Borderline" and "elevated" SEPs occurred in patients with heterogeneous neurologic disorders. Follow-up recordings showed inconsistent results: seven children had amplitudes > 14 microV in all recordings, six only at the first examination, and six only at follow-up. In six children with hemiparesis enhanced SEPs were recorded over both (n = 2) or only over the unaffected hemisphere (n = 4). Myoclonic seizures were observed only in five children with NCL. Similar to other SEP parameters, enhanced amplitudes are an unspecific indicator of an ongoing neurologic disorder. However, in neuronal ceroid lipofuscinosis, enhanced SEP amplitudes may be a useful diagnostic criterium.

Adolescent↗

Feline mucopolysaccharidosis VII due to beta-glucuronidase deficiency.

A male cat 12-14 weeks old had walking difficulties and an enlarged abdomen. Facial dysmorphism, plump paws, corneal clouding, granulation of neutrophils, vacuolated lymphocytes, and a positive urine test for sulfated glycosaminoglycans suggested mucopolysaccharidosis. Cultured fibroblasts incorporated 35SO4 into mucopolysaccharides more actively than did fibroblasts of a feline control, and degradation was far inferior. Activity of beta-glucuronidase was absent in leukocytes and markedly reduced in fibroblasts, thus establishing the diagnosis of mucopolysaccharidosis VII, a disorder previously described in humans, dogs, and mice. Light microscopic examination revealed foam cells in virtually all organs examined, and electron microscopic examination showed pancytic storage of floccular material characteristic of mucopolysaccharides. Stored sphingolipids in the form of zebra bodies were seen in ganglion cells of the central nervous system and in smooth muscle cells of blood vessels. This case represents another animal model of mucopolysaccharidosis VII with the full disease characteristics known in human patients.

Animals↗

Prenatal diagnosis of collagen disorders by direct biochemical analysis of chorionic villus biopsies.

We have developed a method for early prenatal diagnosis of molecular disorders of collagens I and III. The method takes advantage of the fact that isolated chorionic villi contain significant amounts of collagens in their extracellular matrix (stroma) and that they synthesize collagens in vitro. After metabolic labeling of chorion villus biopsies in toto with radioactive amino acids, collagens are extracted and analyzed by SDS-PAGE. Direct staining of the gel shows collagens synthesized in vivo, whereas autoradiofluorography identifies collagens synthesized during incubation in vitro. Unlike collagens synthesized by cultured amniotic fluid cells, collagens extracted from chorionic villi are not overmodified and thus allow better identification of molecular defects. Results are available within 3 to 5 d after biopsy. Using this method, we have correctly excluded Ehlers-Danlos syndrome type IV in two pregnancies, Ehlers-Danlos syndrome type VII in one pregnancy, and lethal osteogenesis imperfecta in four pregnancies. In addition, we correctly predicted a healthy fetus and an embryo affected with lethal osteogenesis imperfecta in consecutive pregnancies from a couple in which the asymptomatic mother was a somatic mosaic for a COL1A1 G-to-A transition (Gly355Asp). Direct collagen analysis of chorion villus biopsies labeled in toto is rapid and reliable and may become the method of choice for the prenatal diagnosis of selected collagen disorders.

Adult↗

A defect in the metabolic activation of sulfate in a patient with achondrogenesis type IB.

Achondrogenesis type I is a perinatally lethal, short-limb chondrodysplasia. Two types, IA and IB, have been distinguished by radiographic and histological criteria; both types appear to be inherited as autosomal recessive traits. The underlying molecular defects are not known, but histochemical studies have suggested that in achondrogenesis type IB, cartilage matrix is deficient in sulfated proteoglycans. We have studied cartilage extracts of one newborn with achondrogenesis type IB and found that proteoglycans were quantitatively reduced, and, unlike in control cartilage, they did not stain with toluidine blue and did not bind to DEAE. Impaired synthesis of sulfated proteoglycans was observed also in fibroblast cultures of the achondrogenesis IB patient. Radioactive labeling and immunoprecipitation studies indicated that core protein and side chains of proteoglycans were synthesized normally but were not sulfated. Analysis of sulfate metabolism in fibroblast cultures showed, in the patient's cells, normal intracellular levels of free sulfate but markedly reduced levels of the two intermediate compounds in the sulfate activation pathway, adenosine-phosphosulfate and phosphoadenosine-phosphosulfate. The results can be explained by deficient activity of one of the enzymes responsible for the biologic activation of sulfate, possibly similar to that observed in cartilage (but not in skin) of the recessive, nonlethal mouse mutant brachymorphic and leading to defective sulfation of macromolecules. Expression of the sulfation defect in cultured fibroblasts may offer a diagnostic tool for the disorder.

Adenosine Phosphosulfate↗