26
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Palz M, Tiecke F, Booms P, Göldner B, Rosenberg T, Fuchs J, Skovby F, Schumacher H, Kaufmann UC, von Kodolitsch Y, Nienaber CA, Leitner C, Katzke S, Vetter B, Hagemeier C, Robinson PN. Clustering of mutations associated with mild Marfan-like phenotypes in the 3' region of FBN1 suggests a potential genotype-phenotype correlation. AMERICAN JOURNAL OF MEDICAL GENETICS 2000; 91:212-21. [PMID: 10756346 DOI: 10.1002/(sici)1096-8628(20000320)91:3<212::aid-ajmg12>3.0.co;2-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mutations in the gene for fibrillin-1 (FBN1) cause Marfan syndrome, a dominantly inherited disorder of connective tissue that primarily involves the cardiovascular, ocular, and skeletal systems. There is a remarkable degree of variability both within and between families with Marfan syndrome, and FBN1 mutations have also been found in a range of other related connective tissue disorders collectively termed type-1 fibrillinopathies. FBN1 mutations have been found in almost all of the 65 exons of the FBN1 gene and for the most part have been unique to one affected patient or family. Aside from the "hot spots" for the neonatal Marfan syndrome in exons 24-27 and 31-32, genotype-phenotype correlations have been slow to emerge. Here we present the results of temperature-gradient gel electrophoresis analysis of FBN1 exons 59-65. Six mutations were identified, only one of which had been previously reported. Two of the six mutations were found in patients with mild phenotypes. Taken together with other published reports, our results suggest that a sizable subset (ca. 40%) of mutations in this region is associated with mild phenotypes characterized by the lack of significant aortic pathology, compared with about 7% in the rest of the gene. In two cases, mutations affecting analogous positions within one of the 43 cbEGF modules of FBN1 are associated with mild phenotypes when found in one of the 6 C-terminal modules (encoded by exons 59-63), but are associated with classic or severe phenotypes when found in cbEGF modules elsewhere in the gene.
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Lund AM, Skovby F, Knudsen FU. [Child abuse and osteogenesis imperfecta. How do we distinguish?]. Ugeskr Laeger 2000; 162:1528-33. [PMID: 10868105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Osteogenesis imperfecta is a hereditary connective tissue disorder. Typical manifestations are fragile bones with multiple bone fractures and bone deformities. A history of minimal or no trauma and recurrent fractures is a feature of OI, but is also typical of non-accidental injury (NAI). OI and NAI are relevant differential diagnoses when a child presents with unexplained fractures. The differential diagnostic problems are reviewed, all of which are important for the child both in terms of treatment and for prognosis, socially and medicolegally. We conclude that comprehensive clinical evaluation is adequate for differential diagnosis and that both OI and NAI can be diagnosed by positive anamnestic and objective signs. Mild OI IV without other signs than fracture(s) is very rare and the new entity temporary brittle bone disease is hypothetical; the diagnosis of these two clinical pictures is unacceptable in small children. Routine analysis of collagens should not be performed.
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Kjaer I, Hansen BF, Kjaer KW, Skovby F. Abnormal timing in the prenatal ossification of vertebral column and hand in Crouzon syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 2000; 90:386-9. [PMID: 10706360 DOI: 10.1002/(sici)1096-8628(20000228)90:5<386::aid-ajmg8>3.0.co;2-m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report on a radiographically examined fetus (gestational age 13 weeks) with Crouzon syndrome caused by a mutation in the gene encoding the fibroblast growth factor 2 (FGFR2). We found an approximately 2-week delay in vertebral body and hand ossification with normal vertebral arch ossification, suggesting that regionally delayed skeletal maturation might be a manifestation of FGFR2 mutation syndromes. The findings support other studies indicating that different signaling pathways control skeletal maturation in vertebral bodies and vertebral arches.
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29
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Nielsen JB, Skovby F. [Rett syndrome: congenital defect of a transcription inhibitory protein]. Ugeskr Laeger 2000; 162:672. [PMID: 10707603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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30
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Kjaergaard S, Skovby F, Schwartz M. Carbohydrate-deficient glycoprotein syndrome type 1A: expression and characterisation of wild type and mutant PMM2 in E. coli. Eur J Hum Genet 1999; 7:884-8. [PMID: 10602363 DOI: 10.1038/sj.ejhg.5200398] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We have identified the PMM2 genotypes of 22 unrelated Danish patients with carbohydrate-deficient glycoprotein syndrome type 1A: R141H/F119L (18), R141H/C192G (1), F119L/F119L (1), F119L/G117R (1) and D223E/T237R (1). The lack of patients homozygous for R141H is statistically highly significant, but unexplained. In order to investigate the effect of PMM2 mutations on phosphomannomutase (PMM2) activity, PMM2-cDNA was cloned into a pET3a vector. Following introduction of mutations into PMM2-cDNA by site-specific mutagenesis, wild type and mutant PMM2-cDNA were expressed in E. coli Bl21(DE3) cells, and the activity of PMM2 was determined by an enzymatic assay using mannose 1-phosphate as substrate. Recombinant R141H, G117R, and T237R PMM2 had no detectable catalytic activity, and the F119L PMM2 had 25% of the activity of the wild type. The activity of the C192G and D223E PMM2 was in the normal range, but the affinity for their substrate was lower, and the proteins were more sensitive to increased temperatures. Each patient has at least one mutation which retains residual PMM2 activity. Our results support the hypotheses that a genotype conveying residual PMM2 catalytic activity is required for survival, and that homozygosity for R141H impairs PMM2 to a degree incompatible with life.
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31
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Lund AM, Mølgaard C, Müller J, Skovby F. Bone mineral content and collagen defects in osteogenesis imperfecta. Acta Paediatr 1999; 88:1083-8. [PMID: 10565454 DOI: 10.1080/08035259950168135] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Whole-body and spine dual-energy X-ray absorptiometry was done in 63 patients with osteogenesis imperfecta aged 5 to 63 y, and the results were compared with OI types and collagen defects. Bone mineral content (BMC)-for-age, bone area (BA)-for-age, bone mineral density (BMD)-for-age, and BMC-for-BA were reduced, especially in patients with OI III/IV and/or in those with a qualitative collagen defect. BA-for-height was normal. Some patients with OI I and/or a quantitative collagen defect had BMD at or above -2 z-scores. We conclude (i) that both BMC and BMD differ significantly between OI types and collagen defects, (ii) that reduced BMC-for-age in OI patients is due mainly to reduced height ("short bones") and reduced BMC-for-BA ("light bones"), whereas BA-for-height ("bone width") is normal, (iii) that most OI patients have lower than average BMC, but in some mildly affected patients brittleness may exist with only small reductions in BMC.
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32
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Murakami A, Skovby F, Andreasen JO, Cohen MM, Jensen BL, Kreiborg S. Oral manifestations of Schimmelpenning syndrome: case report and review of literature. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1999; 28:744-8. [PMID: 10597363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Schimmelpenning syndrome (SS) is characterised by specific skin manifestations, skeletal defects, and central nervous system abnormalities. Here, the SS is briefly reviewed, and the oral and dental manifestations are described in a patient whose medical findings were previously published and included severe hypophosphatemic rickets. Significant oral and dental features included papillomatous lesions of the gingiva, hemihyperplasia (hemihypertrophy) of the tongue, bone cysts, aplasia of teeth, enlarged pulp chambers, hypoplastic or absent enamel, and an odontodysplasia-like permanent tooth.
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Abstract
Standing height, sitting height, armspan, subischial leg length, head circumference, and growth hormone-insulin-like growth factor I (IGF-I) axis were determined in 86 patients with osteogenesis imperfecta. The aim of this study was to determine standing height and body proportions and their variability among osteogenesis imperfecta types and collagen defects. Mean standing height was reduced in all groups of patients, to the greatest extent and variability in osteogenesis imperfecta type III/IV and in those with qualitative collagen defects. The mean standing height of patients with osteogenesis imperfecta was lower than that of their unaffected first degree family members. Truncal height of patients with osteogenesis imperfecta was reduced; head size was increased, and this was more pronounced in patients with osteogenesis imperfecta type III/IV and qualitative collagen defects than in patients with osteogenesis imperfecta type I and quantitative collagen defects. Mean concentrations of IGF-I and IGF binding protein 3 (IGFBP-3) were low, but most values were within age specific reference values. The reduction of standing height appears to correlate with osteogenesis imperfecta type and the type of collagen defect. A relatively short trunk is typical and head circumference and body length are disproportionate.
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Simonsen H, Nørgaard-Pedersen B, Skovby F. [Information to health personnel on increased examination of inborn metabolic errors in newborn infants]. Ugeskr Laeger 1999; 161:1281. [PMID: 10083830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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35
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Skovby F. [Treatment of hereditary and malignant diseases by regulating genetic transcription?]. Ugeskr Laeger 1998; 160:7447. [PMID: 9889663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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36
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Kjaergaard S, Graem N, Larsen T, Skovby F. Recurrent fetal polycystic kidneys associated with glutaric aciduria type II. APMIS 1998; 106:1188-93. [PMID: 10052728 DOI: 10.1111/j.1699-0463.1998.tb00276.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A woman had two pregnancies terminated in the 20th and 21st weeks of gestation after ultrasonographic detection of enlarged hyperechoic kidneys in both fetuses. The combination of polycystic kidneys and steatotic liver found at autopsy suggested glutaric aciduria type II (GA II), which was confirmed by biochemical investigation. GA II or multiple acyl-CoA dehydrogenase deficiency is an autosomal recessively inherited defect of mitochondrial energy metabolism, which usually results in neonatal death. When pregnancy is terminated because of enlarged hyperechoic kidneys in the fetus, autopsy is crucial for establishing the correct diagnosis. The combination of polycystic kidneys and steatotic liver should bring GA II to mind, and prompt appropriate biochemical investigations so that genetic counselling and first trimester diagnosis can be offered in future pregnancies.
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Lund AM, Hansen M, Kollerup G, Juul A, Teisner B, Skovby F. Collagen-derived markers of bone metabolism in osteogenesis imperfecta. Acta Paediatr 1998; 87:1131-7. [PMID: 9846914 DOI: 10.1080/080352598750031112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Markers of bone formation [C-terminal and N-terminal propeptides of procollagen I (PICP, PINP), osteocalcin and alkaline phosphatase] and bone resorption [C-terminal cross-linked telopeptide of collagen I (ICTP) and hydroxypyridinium cross-links, pyridinoline (Pyr) and deoxypyridinoline (Dpyr)] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low, and the serum levels were lower in all children and adults with mild OI and a quantitative collagen defect than in patients with severe OI and a qualitative collagen I defect. ICTP, Pyr and Dpyr were generally normal or reduced, but elevated in severely affected adults with a qualitative collagen I defect. The in vivo findings correlated with in vitro results of collagen I SDS-PAGE. Bone turnover is reduced in OI children and mildly affected OI adults, whereas bone resorption is elevated in severely affected adults. These findings may prove helpful for diagnosis and decision-making regarding therapy in OI.
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38
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Skovby F. [Neonatal screening for hereditary diseases]. Ugeskr Laeger 1998; 160:5765. [PMID: 9782752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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39
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Kjaergaard S, Kristiansson B, Stibler H, Freeze HH, Schwartz M, Martinsson T, Skovby F. Failure of short-term mannose therapy of patients with carbohydrate-deficient glycoprotein syndrome type 1A. Acta Paediatr 1998; 87:884-8. [PMID: 9736238 DOI: 10.1080/080352598750013680] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Carbohydrate-deficient glycoprotein syndrome type 1A (CDGS1A) is an inherited disorder with multisystemic abnormalities resulting from failure to generate sufficient lipid-linked oligosaccharide precursor or to transfer the sugar chain to many glycoproteins. Cultured fibroblasts from these patients have reduced incorporation of mannose into glycoproteins which can be corrected by adding D-mannose to the culture medium. Providing dietary mannose to elevate mannose concentrations in vivo therefore might remedy some of the underglycosylation in the patients. Five children with CDGS1A aged 15 months to 14 y completed a protocol of enteral supplementation with D-mannose 100 mg/kg every 3 h for 9 d. The mean S-mannose level increased from 32 microM (range 22-42 microM) to a trough value of 72 microM (range 39-103 microM). No serious side effects were observed. Surprisingly, the mean serum concentration of four glycoproteins (transferrin, alpha1-antitrypsin, antithrombin, and thyroxine-binding globulin) tended to decrease, and the mean serum concentration of carbohydrate-deficient transferrin (CDT) increased. Furthermore, the initially present abnormal isoforms of these glycoproteins and of protein C became more prominent and/or additional abnormal isoforms appeared. This short-term trial does not support a benefit of mannose to the deficient glycosylation of CDGS1A patients.
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Kjaergaard S, Skovby F, Schwartz M. Absence of homozygosity for predominant mutations in PMM2 in Danish patients with carbohydrate-deficient glycoprotein syndrome type 1. Eur J Hum Genet 1998; 6:331-6. [PMID: 9781039 DOI: 10.1038/sj.ejhg.5200194] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Carbohydrate-deficient glycoprotein syndrome type 1 (CDG1; McKusick No. 212065) is an autosomal recessively inherited disease characterised clinically by central nervous system dysfunction and biochemically by hypoglycosylation of many serum proteins. Most patients with CDG1 have deficient activity of phosphomannomutase. The locus for this enzyme has been mapped to 16p13, and a gene, PMM2, encoding phosphomannomutase has been isolated. We identified 34 mutations on 36 disease chromosomes in 18 unrelated Danish patients with CDG1. All patients have less than 15% residual activity of phosphomannomutase. Two mutations account for 88% of all mutations: F119L and R141H were each found in 16 out of 36 CDG1 alleles. These two mutations were found to be in linkage disequilibrium with two different alleles of the marker D16S3020, suggesting that there is one ancestral origin for each mutation. Two new mutations, G117R and D223E, were identified also. Surprisingly, no patient was homozygous for either of the two common mutations, suggesting that homozygosity for these mutations is either lethal or so benign that such patients are not detected.
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41
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Rasmussen LB, Andersen NL, Andersson G, Lange AP, Rasmussen K, Skak-Iversen L, Skovby F, Ovesen L. Folate and neural tube defects. Recommendations from a Danish working group. DANISH MEDICAL BULLETIN 1998; 45:213-7. [PMID: 9587705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A working group was established to evaluate the need for an increased folate intake in Danish women to decrease the risk of neural tube defects (NTDs). NTD are birth defects which include anencephaly, encephalocele and spina bifida. In Denmark the incidence is about 1.4 per 1,000 pregnancies. Folate is a B-vitamin found in most food groups. In case-control studies and randomised studies, a protective effect of folic acid supplements on NTDs has been found. The studies show that a periconceptional folic acid supplement of 360 micrograms to 4 mg daily decreases the recurrence rate of NTDs. Likewise, in the few studies which calculate folate intake from the diet, a lower risk of NTD with higher intake of folate from the diet has been found. The folate intake can be increased by the diet, by folic acid supplements or by fortification of food with folic acid. It is concluded that the incidence of NTDs in Denmark will decrease if the folate intake in fertile women increases. All women planning pregnancy should receive dietary counselling. Women who do not eat according to the Nordic Nutrition Recommendations, and women with an increased risk due to diseases are recommended a supplement of 400 micrograms folic acid daily from a multivitamin/folic acid tablet. Women who have had a child with NTD and women who themselves have NTDs are recommended a supplement of 5 mg folic acid daily. Dietary changes and supplements should be initiated when pregnancy is planned.
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Lund AM, Jensen BL, Nielsen LA, Skovby F. Dental manifestations of osteogenesis imperfecta and abnormalities of collagen I metabolism. JOURNAL OF CRANIOFACIAL GENETICS AND DEVELOPMENTAL BIOLOGY 1998; 18:30-37. [PMID: 9594376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The in vitro protein-chemical features and the molecular background of osteogenesis imperfecta (OI), a heritable disorder of collagen I metabolism, have been elucidated in recent years. The aim of our study was to find the prevalence of dentinogenesis imperfecta (DI) and other dental anomalies in 88 patients with OI, to compare clinical with radiologic abnormalities, and to correlate these clinical/radiologic findings with the results of gel electrophoresis and molecular studies of collagen I. Twenty-eight percent of OI patients had DI. Most patients with DI had radiologic abnormalities, but some patients had radiologic signs compatible with DI, but no clinical signs of DI. OI type I patients with DI were more severely affected by OI than those without DI. In OI type III and IV, in contrast, there was no difference in overall severity between patients with and without DI. DI was not associated with any particular molecular aberration in any OI type. If defining DI from the presence of both clinical and radiologic signs, collagen I produced by cultured fibroblasts was qualitatively abnormal from all OI patients with DI. Some OI patients had dental abnormalities not resembling DI. A qualitative collagen abnormality could not be found in any of these patients. Denticles, i.e., calcifications within the pulpal cavity, were found more frequently in OI patients than in control subjects.
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Warburg M, Jensen H, Prause JU, Bolund S, Skovby F, Miranda MJ. Anophthalmia-microphthalmia-oblique clefting syndrome: confirmation of the Fryns anophthalmia syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 1997; 73:36-40. [PMID: 9375920 DOI: 10.1002/(sici)1096-8628(19971128)73:1<36::aid-ajmg8>3.0.co;2-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We describe a patient with bilateral extreme microphthalmia with bilateral congenital glaucoma, bilateral medial oblique facial cleft ending in lid colobomas, bilateral stenosis of the choanae, bifid uvula, frontal encephalocele, and premature craniosynostosis. The cause is unknown, but the phenotype resembles the Fryns anophthalmia-plus syndrome, which may be a recessive trait, although intrauterine environmental factors cannot be excluded.
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Panneerselvam K, Etchison JR, Skovby F, Freeze HH. Abnormal metabolism of mannose in families with carbohydrate-deficient glycoprotein syndrome type 1. BIOCHEMICAL AND MOLECULAR MEDICINE 1997; 61:161-7. [PMID: 9259981 DOI: 10.1006/bmme.1997.2599] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Patients with carbohydrate-deficient glycoprotein syndrome (CDGS) Type 1 underglycosylate many glycoproteins by failing to add entire N-linked carbohydrate chains to them. The primary defect in these patients has been reported as a > 90% deficiency in phosphomannomutase activity (PMM), the enzyme that converts mannose-6-phosphate to mannose-1-phosphate. This lesion reduces both the amount and the size of the lipid-linked oligosaccharide precursor. We have now analyzed the activity of PMM and the level of glycosylation in cultured fibroblasts as well as the level of blood mannose in seven CDGS Type 1 patients and their parents. All of these patients were approximately 95% deficient in PMM activity and their parents had an average of 51% of control PMM activity. Furthermore, parental fibroblasts showed reduced glycosylation and a higher proportion of truncated N-linked chains compared to those made by control fibroblasts. Addition of 0.25 mM mannose to the culture medium corrected both the underglycosylation and size of the oligosaccharide chains in CDGS Type 1 patients and their parents. Finally, serum from CDGS patients had considerably reduced mannose levels (5-40 microM) compared to normal controls (40-80 microM) and some parents were below normal (16-103 microM). These results suggest that the reduced blood mannose level is a consequence of the PMM deficiency. This is the first inherited disorder in human metabolism that shows a decrease in available mannose. Increasing blood mannose levels might correct some protein underglycosylation in these patients.
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Lund AM, Nicholls AC, Schwartz M, Skovby F. Parental mosaicism and autosomal dominant mutations causing structural abnormalities of collagen I are frequent in families with osteogenesis imperfecta type III/IV. Acta Paediatr 1997; 86:711-8. [PMID: 9240878 DOI: 10.1111/j.1651-2227.1997.tb08573.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Protein-chemical and molecular studies were conducted on all osteogenesis imperfecta (OI) type III/IV patients referred to our hospital during the last 15 y. Of a total of 16 OI type III/IV patients studied, 15 patients were heterozygous for a mutation in one of the two genes coding for collagen I, COL1A1 or COL1A2. Cultured fibroblasts from these 15 patients produced both normal and abnormal collagen I molecules, pointing to a dominant-negative effect of the mutation. Nine mutations had not been described previously. Parental mosaicism was demonstrated in three families. In the 16th child the causative mutation was not found. In conclusion, OI type III/IV in most patients of Western European ancestry is caused by dominant mutations in the genes for collagen I, and recurrence of OI is caused in most cases by parental gonadal mosaicism.
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Alton G, Kjaergaard S, Etchison JR, Skovby F, Freeze HH. Oral ingestion of mannose elevates blood mannose levels: a first step toward a potential therapy for carbohydrate-deficient glycoprotein syndrome type I. BIOCHEMICAL AND MOLECULAR MEDICINE 1997; 60:127-33. [PMID: 9169093 DOI: 10.1006/bmme.1997.2574] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Carbohydrate-deficient glycoprotein syndrome type I (CDGS) is an inherited metabolic disorder with multisystemic abnormalities resulting from a failure to add entire N-linked oligosaccharide chains to many glycoproteins. Fibroblasts from these patients also abnormally glycosylate proteins, but this lesion is corrected by providing 250 microM mannose to the culture medium. This correction of protein glycosylation suggests that providing dietary mannose to elevate blood mannose concentrations might also remedy some of the underglycosylation observed in these patients. We find that ingested mannose is efficiently absorbed and increases blood mannose levels in both normal subjects and CDGS patients. Blood mannose levels increased in a dose-dependent fashion with increasing oral doses of mannose (0.07-0.21 g mannose/kg body weight). Peak blood mannose concentrations occurred at 1-2 h following ingestion and the clearance half-time was approximately 4 h. Doses of 0.1 g mannose/ kg body weight given at 3-h intervals maintained blood mannose concentrations at levels 3- to 5-fold higher than the basal level in both normal controls (approximately 55 microM) and CDGS patients. No side effects were observed for this dosage regimen. These results establish the feasibility of using mannose as a potential therapeutic dietary supplement (nutraceutical) to treat CDGS patients.
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47
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Bjursell C, Stibler H, Wahlström J, Kristiansson B, Skovby F, Strömme P, Blennow G, Martinsson T. Fine mapping of the gene for carbohydrate-deficient glycoprotein syndrome, type I (CDG1): linkage disequilibrium and founder effect in Scandinavian families. Genomics 1997; 39:247-53. [PMID: 9119361 DOI: 10.1006/geno.1996.4488] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Carbohydrate-deficient glycoprotein syndrome type I (CDG I) is characterized clinically by severe nervous system involvement and biochemically by defects in the carbohydrate residues in a number of serum glycoproteins. The CDG1 gene was recently localized by us to a 13-cM interval in chromosome region 16p13. In this study 44 CDG I families from nine countries were analyzed with available markers in a region ranging from marker D16S495 to D16S497, and haplotype and linkage disequilibrium analyses were performed. One specific haplotype was found to be markedly overrepresented in CDG I patients from a geographically distinct region in Scandinavia, strongly indicating that CDG I families in this region share the same ancestral CDG1 mutation. furthermore, analysis of the extent of the common haplotype in these families indicates that the CDG1 gene is located in the region defined by markers D16S513-AFMa284wd5-D16S768-D16S406-D16S502 . The critical CDG1 region, in strong linkage disequilibrium with markers AFMa284wd5, D16S768, and D16S406, thus constitutes less than 1 Mb of DNA and less than 1 cM in the very distal part of the CDG1 region defined by us previously.
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Brøndum-Nielsen K, Beck B, Gyftodimou J, Hørlyk H, Liljenberg U, Petersen MB, Pedersen W, Petersen MB, Sand A, Skovby F, Stafanger G, Zetterqvist P, Tommerup N. Investigation of deletions at 7q11.23 in 44 patients referred for Williams-Beuren syndrome, using FISH and four DNA polymorphisms. Hum Genet 1997; 99:56-61. [PMID: 9003495 DOI: 10.1007/s004390050311] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Williams syndrome (WS) is associated with a submicroscopic deletion of the elastin gene (ELN) at 7q11.23. The deletion encompasses closely linked DNA markers. We have investigated 44 patients referred for possible WS using fluorescence in situ hybridization (FISH) analysis with a P1 clone containing an insert from the ELN, as well as performing genotype analysis of patients and parents with four DNA polymorphisms. Twenty-four patients were found to have deletions, 19 of whom were found clinically to have typical WS. The facial features were especially characteristic. None of the patients without detectable deletions was reported to have typical WS features, although one had supravalvular aortic stenosis, hypercalcemia, and mental retardation. No evidence was found in this material for variability of the size of the deletion. Our study supports the usefulness of analysis of ELN deletion in WS patients, both for confirmation of diagnosis and for genetic counselling.
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Schwartz M, Sørensen N, Hansen FJ, Hertz JM, Nørby S, Tranebjaerg L, Skovby F. Quantification, by solid-phase minisequencing, of the telomeric and centromeric copies of the survival motor neuron gene in families with spinal muscular atrophy. Hum Mol Genet 1997; 6:99-104. [PMID: 9002676 DOI: 10.1093/hmg/6.1.99] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In an analysis of 30 families affected by spinal muscular atrophy (SMA) we have used the solid-phase minisequencing method to determine the ratio between the number of telomeric and centromeric copies of the survival motor neuron gene (SMN and cBCD541 respectively) on normal and SMA chromosomes. This has enabled us to establish haplotypes with regard to SMN and cBCD541, and estimate their frequencies, on both types of chromosomes. Six predominant haplotypes were identified, three for normal chromosomes and three for SMA chromosomes, characterized by having 0, 1, or 2 copies, respectively, of cBCD541. We found evidence for the presence of patients homozygous for a deletion of SMN and with only one copy of cBCD541, but found none deleted for all copies of this gene. Several asymptomatic carriers of SMA with only a single copy of SMN and no copy of cBCD541 were identified. We could not confirm the hypothesis that the presence of more copies of cBCD541 is correlated to a less severe course of the disease. The frequencies of haplotypes characterized by having 0, 1, or 2 copies, respectively, of cBCD541 were found to differ significantly between normal and SMA chromosomes. This distribution can be explained by an underrepresentation of the haplotype completely lacking SMN genes, which is expected to cause early embryonic death in homozygotes. This first report of a direct haplotype analysis of SMN and cBCD541 should help clarify the role of cBCD541 in the pathogenesis of SMA.
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Lund AM, Schwartz M, Skovby F. Variable clinical expression in a family with OI type IV due to deletion of three base pairs in COL1A1. Clin Genet 1996; 50:304-9. [PMID: 9007315 DOI: 10.1111/j.1399-0004.1996.tb02379.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have studied a family with autosomal dominant osteogenesis imperfecta (OI) type IV. Electrophoresis of collagen produced by cultured fibroblasts revealed a slower migrating population of collagen I. Cyanogen bromide peptide mapping localised the structural defect to the area of the alpha 1(1)CB3 peptide. Subsequent sequencing revealed a deletion of nucleotides 1964-1966 in exon 27 of COL1A1. By means of restriction enzyme analysis, the deletion could be detected in all affected family members. This in-frame deletion resulted in the removal of alanine-438 and Glu437Asp substitution in the pro alpha 1(I) collagen chain. Clinical variation was considerable among affected family members. The most consistent clinical features were reduced height and extraosseous manifestations of OI.
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