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ABSTRACT: Gene therapy may provide a long-term approach to the treatment of mucopolysaccharidoses. As a first step toward the development of an effective gene therapy for mucopolysaccharidosis type IVA (Morquio syndrome), a recombinant retroviral vector, LGSN, derived from the LXSN vector, containing a full-length human wildtype N-acetylgalactosamine-6-sulfate sulfatase (GALNS) cDNA, was produced. Severe Morquio and normal donor fibroblasts were transduced by LGSN. GALNS activity in both Morquio and normal transduced cells was several fold higher than normal values. To measure the variability of GALNS expression among different transduced cells, we transduced normal and Morquio lymphoblastoid B cells and PBLs, human keratinocytes, murine myoblasts C2C12, and rabbit synoviocytes HIG-82 with LGSN. In all cases, an increase of GALNS activity after transduction was measured. In Morquio cells co-cultivated with enzyme-deficient transduced cells, we demonstrated enzyme uptake and persistence of GALNS activity above normal levels for up to 6 days. The uptake was mannose-6-phosphate dependent. Furthermore, we achieved clear evidence that LGSN transduction of Morquio fibroblasts led to correction of the metabolic defect. These results provide the first evidence that GALNS may be delivered either locally or systematically by various cells in an ex vivo gene therapy of MPS IVA.
Human Gene Therapy 12/2001; 12(16):2007-16. · 4.22 Impact Factor
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ABSTRACT: Peroxisome biogenesis disorders (PBDs) are severe autosomal recessive neurological diseases caused by a defect of peroxisomal assembly factors. Zellweger syndrome, the most severe phenotype, is characterized by hypotonia, psychomotor retardation and neuronal migration disorder. Neonatal adrenoleukodystrophy and infantile Refsum disease are milder phenotypes of this disease. Thirteen complementation groups have been established since the genetic heterogeneity of PBDs was elucidated in 1988. Eleven genes for PBDs have been identified either by a functional complementation cloning or by EST homology searches. In 1992, the first gene for PBDs, PEX2, was identified. It encodes peroxisomal integral membrane protein with a RING finger domain. PEX5 and PEX7 are the genes for peroxisomal targeting signal (PTS)-1 and -2 receptors, respectively. PEX3, PEX16 and PEX19 are considered to be required for the early stage of peroxisome biogenesis. PEX13 protein has an SH3 docking site that binds to the PTS-1 receptor. PEX1 and PEX6 encode ABC protein, and PEX10 and PEX12 also encode integral membrane protein, with RING finger. Temperature-sensitivity, whereby peroxisomal biogenesis and metabolic dysfunctions are restored at 30 degrees C in cells from mild phenotypes, is a useful event for predicting the clinical severity and for elucidation of peroxisome biogenesis. Investigations using knockout mice are expected to facilitate understanding of migration disorders.
Journal of Inherited Metabolic Disease 05/2001; 24(2):151-65. · 3.58 Impact Factor
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A M Montaño,
A Yamagishi,
S Tomatsu, S Fukuda,
N G Copeland,
K E Orii,
K Isogai,
N Yamada,
Z I Kato,
N A Jenkins,
D J Gilbert,
K Sukegawa,
T Orii,
N Kondo
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ABSTRACT: Deficiency of lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS) leads to mucopolysaccharidosis IV A (MPS IV A), for which there is no definitive treatment so far. Although a number of mutations of the GALNS gene of MPS IV A patients have been described, pathogenesis of the disorder still remains elusive. In order to facilitate in vivo studies using model animals for MPS IV A, we isolated and performed molecular characterization of the mouse homolog of human GALNS. The 2.3-kb cDNA contains a 1560-bp open reading frame encoding 520 amino acid residues. The coding region has 84% similarity to the human GALNS cDNA at amino acid level. The mouse Galns gene was mapped by interspecific backcross analysis to the distal region of chromosome 8 where it co-segregates with Aprt. Northern blot analysis showed a wide expression of a single-copy gene, being higher especially in liver and kidney. The Galns gene was isolated from S129vJ genomic library and its genomic organization was characterized. The mouse Galns gene was about 50-kb long and organized into 14 exons and 13 introns. All intron-exon splice junctions conformed to the GT/AG consensus sequence except exon 8/intron 8 junction. Primer extension shows multiple transcription initiation sites between -44 and -75 although major transcription initiation site was observed at -90 bp from the ATG codon. The 5'-flanking region lacks canonical TATA and CAAT box sequences, but is G+C rich with 10 GC boxes (potential Sp1 binding sites), characteristic of a housekeeping gene promoter.
Biochimica et Biophysica Acta 04/2000; 1500(3):323-34. · 4.66 Impact Factor
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Z Zhang,
Y Suzuki,
N Shimozawa, S Fukuda,
A Imamura,
T Tsukamoto,
T Osumi,
Y Fujiki,
T Orii,
R J Wanders,
P G Barth,
H W Moser,
B C Paton,
G T Besley,
N Kondo
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ABSTRACT: The PEX6 (peroxisome assembly factor-2, PAF-2) gene encodes a member of the AAA protein (ATPases associated with diverse cellular activities) family and restores peroxisome assembly in fibroblasts from peroxisome biogenesis disorder patients belonging to complementation group C (group 4 in the United States). We have now clarified the genomic DNA structure of human PEX6 and identified mutations in patients from various ethnic groups. The human PEX6 gene consists of 17 exons and 16 introns, spanning about 14kb. The largest exon, exon 1, has at least 952 bp nucleotides. Eleven novel mutations (18 alleles) were identified by direct sequencing of the PEX6 cDNA from 10 patients. All these mutations have been confirmed in the corresponding genomic DNA. There was no common mutation, but an exon skip was identified in two unrelated Japanese patients. Most of the mutations led to premature termination or large deletions of the PEX6 protein and resulted in the most severe peroxisome biogenesis disorder phenotype of Zellweger syndrome. A patient with an atypical Zellweger syndrome had a missense mutation that was shown to disrupt the cell's ability to form peroxisomes. This mutation analysis will aid in understanding the functions of the PEX6 protein in peroxisomal biogenesis. Hum Mutat 13:487-496, 1999.
Human Mutation 02/1999; 13(6):487-96. · 5.69 Impact Factor
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Y Yamada,
K Kato,
K Sukegawa,
S Tomatsu, S Fukuda,
S Emura,
S Kojima,
T Matsuyama,
W S Sly,
N Kondo,
T Orii
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ABSTRACT: A 12-year-old girl with Sly disease (mucopolysaccharidosis VII; beta-glucuronidase deficiency), who is homozygous for the A619V mutation, had a successful allogeneic BMT, donored by an HLA-identical unrelated female to replace the deficient enzyme. Within 5 months after BMT, the enzyme activity of the recipient's lymphocytes increased to normal range. No signs of acute or chronic GVHD were observed. For the successive 31 months post-BMT, beta-glucuronidase activity in her lymphocytes was maintained at almost normal levels and excretion of glycosaminoglycans in the urine was greatly diminished. Ultrastructural findings demonstrated no abnormal vacuoles and inclusion bodies in the cytoplasm of her rectal mucosal cells. Coincident with the restoration of the enzyme activity, clinical improvement was dramatic. Especially notable were improvements in motor function. The patient was able to walk alone for a long time without aid, and she even became able to ride a bicycle and take a bath. In addition, recurrent infections of the upper respiratory tract and the middle ears decreased in frequency and severity, and dyspnea on exertion, severe snoring and vertigo have substantially improved. Thus, allogeneic BMT in this patient produced a better quality of life and provided a more promising outlook.
Bone Marrow Transplantation 03/1998; 21(6):629-34. · 3.75 Impact Factor
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Clinical Genetics 03/1998; 53(2):153-4. · 3.13 Impact Factor
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ABSTRACT: Hunter disease is an X-linked recessive disorder caused by a deficiency of iduronate-2-sulfatase activity. We describe a pair of brother/sister siblings with a typical feature of Hunter disease (mucopolysaccharidosis type II). They had normal karyotypes but a marked deficiency of iduronate-2-sulfatase activity in both lymphocytes and fibroblasts. The molecular analysis of the iduronate-2-sulfatase gene revealed the R468L(G1403-->T) substitution in their genes. Although the sister's genomic DNA was heterozygous for the mutant allele, the sister's cDNA was found to be homogeneous for this mutation. The mother was found to be a heterozygote. The analysis of X chromosome inactivation by comparison of the methylation patterns of the androgen-receptor (AR) gene which was isolated from the sister's fibroblasts and leucocytes revealed a skewed X chromosome inactivation of the paternal allele. These findings indicate that a skewed X chromosome inactivation of the paternal gene and a point mutation in the maternal gene were responsible for the lack of iduronate-2-sulfatase activity in the sister.
Clinical Genetics 03/1998; 53(2):96-101. · 3.13 Impact Factor
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S Tomatsu, S Fukuda,
A Cooper,
J E Wraith,
A Yamagishi,
Z Kato,
N Yamada,
K Isogai,
K Sukegawa,
Y Suzuki,
N Shimozawa,
N Kondo,
T Orii
Human Mutation 02/1998; Suppl 1:S42-6. · 5.69 Impact Factor
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ABSTRACT: Deficiency of enoyl-CoA hydratase: 3-hydroxyacyl-CoA dehydrogenase (peroxisomal bifunctional enzyme), one of the enzymes of the peroxisomal beta-oxidation system, leads to clinical manifestations resembling Zellweger syndrome with hypotonia, psychomotor delay, hepatomegaly, typical facial appearance and accumulation of very long-chain fatty acids. The nucleotide sequence of the human peroxisomal enoyl-CoA hydratase: 3-hydroxyacyl-CoA dehydrogenase cDNA has been reported by Hoefler and colleagues; however, we have found some amino acid differences from our originally isolated cDNA. Contrary to the findings described in a previous paper, we report here the cDNA sequence of human peroxisomal enoyl-CoA hydratase: 3-hydroxyacyl-CoA dehydrogenase in which there are 9 authenticated amino acid alterations.
Journal of Inherited Metabolic Disease 02/1998; 21(1):23-8. · 3.58 Impact Factor
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ABSTRACT: Our series of studies on Hunter disease in Japanese patients showed allelic heterogeneity of IDS gene mutations, genotype/phenotype correlation and racial differences in distribution of mutations. Twenty-five different small mutations have been characterized. Small mutations in the Japanese population are widely distributed through the IDS gene, although some mutations were unevenly concentrated on exon 5 (28%) and on exon 9 (24%). Mutations were seen at the same codon 468 in exon 9 in 5 patients. These findings are in good agreement with data on other ethnic groups. Two unique mutations linked to a severe phenotype were apparently associated with aberrant splicings; one was a point mutation within exon 3 (P86L), partially activating a cryptic splice acceptor site at 28 bp downstream from the mutation site within exon 3 and producing a 44-base truncated mRNA, and the other was a point mutation at the consensus sequence of the splice donor site of intron 2, causing exon 2 skipping.
Journal of Inherited Metabolic Disease 02/1998; 21(1):60-70. · 3.58 Impact Factor
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N Yamada, S Fukuda,
S Tomatsu,
V Muller,
J J Hopwood,
J Nelson,
Z Kato,
A Yamagishi,
K Sukegawa,
N Kondo,
T Orii
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ABSTRACT: Mucopolysaccharidosis IVA (MPS IVA) is an autosomal recessive lysosomal storage disorder caused by a genetic defect in N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Previous studies of patients from a British-Irish population showed that the I113F mutation is the most common single mutation among MPS IVA patients and produces a severe clinical phenotype. We studied mutations in the GALNS gene from 23 additional MPS IVA patients (15 from Australia, 8 from Northern Ireland), with various clinical phenotypes (severe, 16 cases; intermediate, 4 cases; mild, 3 cases). We found two common mutations that together accounted for 32% of the 44 unrelated alleles in these patients. One is the T312S mutation, a novel mutation found exclusively in milder patients. The other is the previously described I113F that produces a severe phenotype. The I113F and T312S mutations accounted for 8 (18%) and 6 (14%) of 44 unrelated alleles, respectively. The relatively high residual GALNS activity seen when the T312S mutant cDNA is overexpressed in mutant cells provides an explanation for the mild phenotype in patients with this mutation. The distribution and relative frequencies of the I113F and T312S mutations in Australia corresponded to those observed in Northern Ireland and are unique to these two populations, suggesting that both mutations were probably introduced to Australia by Irish migrants during the 19th century. Haplotype analysis using 6 RFLPs provides additional data that the I113F mutation originated from a common ancestor. The other 9 novel mutations identified in these 23 patients were each limited to a single family. These data provide further evidence for extensive allelic heterogeneity in MPS IVA in British-Irish patients and provide evidence for their transmission to Australia by British-Irish migrants.
Human Mutation 01/1998; 11(3):202-8. · 5.69 Impact Factor
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Y Suzuki,
L L Jiang,
M Souri,
S Miyazawa, S Fukuda,
Z Zhang,
M Une,
N Shimozawa,
N Kondo,
T Orii,
T Hashimoto
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ABSTRACT: Peroxisomal beta-oxidation proceeds from enoyl-CoA through D-3-hydroxyacyl-CoA to 3-ketoacyl-CoA by the D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxy-acyl-CoA dehydrogenase bifunctional protein (d-bifunctional protein), and the oxidation of bile-acid precursors also has been suggested as being catalyzed by the d-bifunctional protein. Because of the important roles of this protein, we reinvestigated two Japanese patients previously diagnosed as having enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (L-bifunctional protein) deficiency, in complementation studies. We found that both the protein and the enzyme activity of the d-bifunctional protein were hardly detectable in these patients but that the active L-bifunctional protein was present. The mRNA level in patient 1 was very low, and, for patient 2, mRNA was of a smaller size. Sequencing analysis of the cDNA revealed a 52-bp deletion in patient 1 and a 237-bp deletion in patient 2. This seems to be the first report of D-bifunctional protein deficiency. Patients previously diagnosed as cases of L-bifunctional protein deficiency probably should be reexamined for a possible d-bifunctional protein deficiency.
The American Journal of Human Genetics 12/1997; 61(5):1153-62. · 10.60 Impact Factor
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Z Kato, S Fukuda,
S Tomatsu,
H Vega,
T Yasunaga,
A Yamagishi,
N Yamada,
A Valencia,
L A Barrera,
K Sukegawa,
T Orii,
N Kondo
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ABSTRACT: Mucopolysaccharidosis IVA (MPS IVA) is an autosomal recessive lysosomal storage disorder caused by a genetic defect in N-acetylgalactosamine-6-sulfate sulfatase (GALNS). In previous studies, we have found two common mutations in Caucasians and Japanese, respectively. To characterize the mutational spectrum in various ethnic groups, mutations in the GALNS gene in Colombian MPS IVA patients were investigated, and genetic backgrounds were extensively analyzed to identify racial origin, based on mitochondrial DNA (mtDNA) lineages. Three novel missense mutations never identified previously in other populations and found in 16 out of 19 Colombian MPS IVA unrelated alleles account for 84.2% of the alleles in this study. The G301C and S162F mutations account for 68.4% and 10.5% of mutations, respectively, whereas the remaining F69V is limited to a single allele. The skewed prevalence of G301C in only Colombian patients and haplotype analysis by restriction fragment length polymorphisms in the GALNS gene suggest that G301C originated from a common ancestor. Investigation of the genetic background by means of mtDNA lineages indicate that all our patients are probably of native American descent.
Human Genetics 12/1997; 101(1):97-101. · 5.07 Impact Factor
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ABSTRACT: We report here a novel splice site mutation in intron 4 of the gene for N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in an Afghanistan girl with severe mucopolysaccharidosis IVA (classical Morquio disease). Direct sequencing revealed a homozygous G to A transition in the conserved splice acceptor site in intron 4 (cagG-->caaG: designated IVS 4(-I) G-->A) which eliminates 144 nucleotides of exon 5 in her GALNS transcript and introduces an immediate premature termination codon (at Trp 141 of exon 4). The IVS 4(-1) G-->A has not been seen in other populations and this is the first report of the molecular basis of classical Morquio disease in an Afghanistan patient.
The Japanese journal of human genetics 06/1997; 42(2):317-22.
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ABSTRACT: Marinesco-Sjögren syndrome is a rare autosomal recessive disorder characterized by cerebellar atrophy, ataxia, cataracts, short stature and varying degrees of mental retardation. A high incidence of malignant disease associated with this syndrome has not so far been reported. We report the case of a 6-year-old girl affected with Marinesco-Sjögren syndrome, who developed acute myeloblastic leukemia (AML, M2), and whose karyotype was 46,XX,t(8;21),(q22;q22) in bone marrow blasts. This is the first report of Marinesco-Sjögren syndrome associated with malignant disorders.
Clinical Genetics 05/1997; 51(4):278-80. · 3.13 Impact Factor
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K Sukegawa,
X Q Song,
M Masuno,
T Fukao,
N Shimozawa, S Fukuda,
K Isogai,
H Nishio,
M Matsuo,
S Tomatsu,
N Kondo,
T Orii
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ABSTRACT: Hunter disease is an X-linked recessive mucopolysaccharide storage disorder caused by iduronate-2-sulfatase deficiency and is rare in females. We describe here findings in a girl with Hunter disease of the severe type. She had a normal karyotype but a marked deficiency of iduronate-2-sulfatase activity in lymphocytes and cultured fibroblasts. In a sequence analysis of the iduronate-2-sulfatase gene, evidence was obtained for the R468Q (G1403 to A) mutation, a common one in Hunter disease. RT-PCR showed her cDNA to represent only the R468Q allele, although at the genomic level she was a heterozygote with one normal allele. Her brother had the R468Q mutation, and their mother was a carrier of this mutation. The fusion products of CHO (TG(R),Neo(R)) with patient's fibroblasts cultured in HAT/G418 selective medium, carried only the maternal allele. However, in genomic DNA from the patient's fibroblasts, only the paternal allele of the androgen receptor gene, a gene subjected to differential methylation of the inactive X-chromosome, was methylated. These findings strongly suggest that the severe form of Hunter disease in this girl was the result of selective expression of the maternal allele carrying the missense mutation R468Q, which in turn resulted from skewed X inactivation of the paternal nonmutant X chromosome.
Human Mutation 02/1997; 10(5):361-7. · 5.69 Impact Factor
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S Tomatsu, S Fukuda,
A Cooper,
J E Wraith,
P Ferreira,
P Di Natale,
P Tortora,
A Fujimoto,
Z Kato,
N Yamada,
K Isogai,
A Yamagishi,
K Sukegawa,
Y Suzuki,
N Shimozawa,
N Kondo,
W S Sly,
T Orii
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ABSTRACT: Mucopolysaccharidosis IVA (MPS IVA) is an autosomal recessive disorder caused by a deficiency of the lysosomal N-acetylgalactosamine-6-sulfate sulfatase. Here, we report our analysis of data on 21 patients of diverse ethnic and geographic origins studied by SSCP and sequencing analysis. Sixteen mutations were detected, including 14 new mutations (11 missense, one premature termination, one splice site alteration, and one cryptic site alteration). The donor splice site mutation (IVS4 + 1G-->A) predicts that normal splicing will be abolished and that translation would lead to an immediate premature termination (W141X). Another novel nucleotide change outside the coding sequence is an intronic alteration (IVS9-42C-->T:ggtcggtgcggttggtgc) creating a potential cryptic donor site. The nucleotide sequence surrounding this alteration is highly suggestive of a consensus donor splice site. All 12 missense and nonsense mutations were shown by transient expression to abolish or greatly reduce GALNS activity, thereby providing an explanation as to why they produce MPS IVA. All mutations were readily confirmed by restriction enzyme or by allelic specific oligonucleotide analysis (ASO). These findings, coupled with previously reported mutations, bring the total of different mutations to 41 among independent families with MPS IVA, illustrating the extensive allelic heterogeneity among mutations producing MPS IVA.
Human Mutation 01/1997; 10(5):368-75. · 5.69 Impact Factor
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S Fukuda,
N Shimozawa,
Y Suzuki,
Z Zhang,
S Tomatsu,
T Tsukamoto,
N Hashiguchi,
T Osumi,
M Masuno,
K Imaizumi,
Y Kuroki,
Y Fujiki,
T Orii,
N Kondo
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ABSTRACT: Peroxisome-biogenesis disorders (PBD) are genetically heterogeneous and can be classified into at least ten complementation groups. We recently isolated the cDNA for rat peroxisome assembly factor-2 (PAF-2) by functional complementation using the peroxisome-deficient Chinese-hamster-ovary cell mutant, ZP92. To clarify the novel pathogenic gene of PBD, we cloned the full-length human PAF-2 cDNA that morphologically and biochemically restores peroxisomes of group C Zellweger fibroblasts (the same as group 4 in the Kennedy-Krieger Institute) and identified two pathogenic mutations in the PAF-2 gene in two patients with group C Zellweger syndrome. The 2,940-bp open reading frame of the human PAF-2 cDNA encodes a 980-amino-acid protein that shows 87.1% identity with rat PAF-2 and also restored the peroxisome assembly after gene transfer to fibroblasts of group C patients. Direct sequencing of the PAF-2 gene revealed a homozygous 1-bp insertion at nucleotide 511 (511 insT) in one patient with group C Zellweger syndrome (ZS), which introduces a premature termination codon in the PAF-2 gene, and, in the second patient, revealed a splice-site mutation in intron 3 (IVS3+1G-->A), which skipped exon 3, an event that leads to peroxisome deficiency. Chromosome mapping utilizing FISH indicates that PAF-2 is located on chromosome 6p21.1. These results confirm that human PAF-2 cDNA restores peroxisome of group C cells and that defects in the PAF-2 produce peroxisome deficiency of group C PBD.
The American Journal of Human Genetics 12/1996; 59(6):1210-20. · 10.60 Impact Factor
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ABSTRACT: Morquio disease (MPS IVA) is an autosomal recessive disorder caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) activity. Patients commonly present in early infancy with growth failure, spondyloepiphyseal dysplasia, corneal opacification, and keratan sulfaturia, but milder forms have been described. We report on a patient who grew normally until age 5 years. Her keratan sulfaturia was not detected until adolescence, and she now has changes restricted largely to the axial skeleton. She has experienced only mildly impaired vision. At age 22, thin-layer chromatography of purified glycosaminoglycans showed some keratan sulfaturia. GALNS activity in fibroblast homogenate supernatants was 20 +/- 5% of controls (as compared to 5 +/- 3% of controls in severe MPS IVA, P < .003). Kinetic analysis of residual fibroblast GALNS activity in patient and parents revealed decreased K(m) and increased Vmax in the mother and daughter, but not in the father, compatible with compound heterozygosity. GALNS exons were amplified from patient genomic DNA and screened by SSCP. Two missense mutations, a C to T transition at position 335 (predicting R94C) and a T to G transversion at position 344 (predicting F97V), were found on sequencing an abnormally migrating exon 3 amplicon. Digestion of the amplicon with FokI and AccI restriction enzymes (specific for the R94C and F97V mutations, respectively) confirmed heterozygosity. In fibroblast transfection experiments, heterozygous R94C and F97V mutants independently expressed as severe and mild GALNS deficiency, respectively. We interpret these findings to indicate that our patient bears heteroallelic GALNS missense mutations, leading to GALNS deficiency and mild MPS IVA. Our findings expand the clinical and biochemical phenotype of MPS IVA, but full delineation of the genotype-phenotype relationship requires further study of native and transfected mutant cell lines.
American Journal of Medical Genetics 07/1996; 63(4):558-65.
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S Tomatsu, S Fukuda,
A Yamagishi,
A Cooper,
J F Wraith,
T Hori,
Z Kato,
N Yamada,
K Isogai,
K Sukegawa,
N Kondo,
Y Suzuki,
N Shimozawa,
T Orii
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ABSTRACT: We report four new mutations in Japanese patients with mucopolysaccharidosis IVA (MPSIVA) who were heterozygous for a common double gene deletion. A nonsense mutation of CAG to TAG at codon 148 in exon 4 was identified, resulting in a change of Q to a stop codon and three missense mutations. V (GTC) to A (GCC) at codon 138 in exon 4, P (CCC) to S (TCC) at codon 151 in exon 5, and P (CCC) to L (CTC) at codon 151 in exon 5. Introduction of these mutations into the normal GALNS cDNA and transient expression in cultured fibroblasts resulted in a significant decrease in the enzyme activity. V138A and Q148X mutations result in changes of restriction site, which were analyzed by restriction-enzyme assay. P151S and P151L mutations that did not alter the restriction site were detected by direct sequencing or allele specific oligohybridization. Detection of the double gene deletion was initially done using Southern blots and was confirmed by PCR. Haplotypes were determined using seven polymorphisms to the GALNS locus in families with the double gene deletion. Haplotype analysis showed that the common double gene deletion occurred on a single haplotype, except for some variation in a VNTR-like polymorphism. This finding is consistent with a common founder for all individuals with this mutation.
The American Journal of Human Genetics 06/1996; 58(5):950-62. · 10.60 Impact Factor
