OBJECTIVE: To explore the genetic etiology of a patient with mucopolysaccharidosis type II (MPSII). METHODS: The IDS gene of the proband and his mother was detected by Sanger sequencing, agarose gel electrophoresis, real-time PCR and multiple ligation-dependent probe amplification (MLPA). Prenatal diagnosis was performed on amniotic fluid sample. RESULTS: Agarose gel electrophoresis, real-time PCR, and MLPA all showed that exon 2 of IDS gene of the proband was deleted, for which his mother was normal. Prenatal diagnosis showed that the fetus was a normal male. CONCLUSION The de novo deletion of exon 2 of the IDS gene probably underlay the MPSII in this patient. Above finding has broadened the mutation spectrum of the IDS gene. The combined methods for the detection of IDS gene mutations could make accurate prenatal diagnosis for MPSII.
China ; Exons ; Female ; Humans ; Male ; Mucopolysaccharidosis II/genetics* ; Mutation ; Pedigree ; Pregnancy ; Prenatal Diagnosis/methods*

OBJECTIVETo detect potential mutation of iduronate-2-sulfatase (IDS) gene in a family affected with mucopolysaccharidosis type Ⅱ (MPS Ⅱ).

METHODSFor the proband and his unaffected mother, the whole coding sequence of the IDS gene was analyzed with PCR and bidirectional Sanger sequencing.

RESULTSA novel splicing mutation, c.709-1G>A, was detected in the proband, for which his mother was heterozygous.

CONCLUSIONThe c.709-1G>A splicing mutation of the IDS gene is probably causative for the MSP Ⅱ in the proband. Prenatal diagnosis for the mutation may avoid birth of further child affected with this disease.

Base Sequence ; Child ; DNA Mutational Analysis ; methods ; Family Health ; Female ; Genetic Predisposition to Disease ; genetics ; Glycoproteins ; genetics ; metabolism ; Heterozygote ; Humans ; Iduronate Sulfatase ; genetics ; metabolism ; Male ; Mothers ; Mucopolysaccharidosis II ; diagnosis ; enzymology ; genetics ; Mutation

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Male ; Mucopolysaccharidosis II ; genetics ; Pedigree

OBJECTIVETo establish a method of iduronate-2-sulfatase (IDS) activity assay and mutation analysis of IDS gene for the prenatal diagnosis of mucopolysaccharidosis type II (MPSII).

METHODSPrenatal diagnosis of two cases was performed using cultured fetal amniotic fluid cells. Enzyme activity of IDS in cultured fetal amniotic fluid cells extracted from the two pregnant women at high risk of MPS II was measured. Meanwhile, genomic DNA was extracted for fetal gender testing and mutation analysis of the IDS gene.

RESULTSEnzyme activity assay showed that IDS activity in amniotic fluid cells was significantly decreased. IDS gene sequencing showed that the male fetus was hemizygous mutant, and the female fetus was carrier of heterozygous mutation. Therefore the male fetus was an MPS II patient and the female fetus was a mutation carrier.

CONCLUSIONDetermination of IDS activity in fetal amniotic fluid cells together with IDS gene mutation analysis is a rapid, sensitive and accurate method of prenatal diagnosis of MPS II. Using this method, prenatal diagnosis for pregnant women at high risk of MPSII can be achieved.

Base Sequence ; Child ; Child, Preschool ; Exons ; Female ; Glycoproteins ; genetics ; metabolism ; Humans ; Male ; Mucopolysaccharidosis II ; diagnosis ; genetics ; metabolism ; Mutation ; genetics ; Pregnancy ; Prenatal Diagnosis

PURPOSE: Mucopolysaccharidosis II (MPS II) is a lysosomal storage disorder caused by a deficiency of iduronate-2 sulfatase (IdS), which is involved in the degradation of glycosaminoglycan (GAG). In this study, the frequency of fasting hypoglycemia in patients with MPS II was investigated and changes in accumulation of glycogen and GAG in the hepatocytes of IdS-knockout (KO) mice were evaluated before and after recombinant IdS enzyme replacement therapy (ERT). MATERIALS AND METHODS: Plasma glucose levels were evaluated after an 8-hour fast in 50 patients with MPS II. The IdS-KO mice were divided into three groups (group 2; saline, group 3; 0.15 mg/kg of IdS, and group 4; 0.5 mg/kg of IdS); wild-type mice were included as controls (group 1). ERT was initiated intravenously at four weeks of age, and continued every week until 20 weeks of age. RESULTS: The mean glucose level after an 8-hour fast was 94.1 +/- 23.7 mg/dL in the patients with MPS II. Two (4%) out of 50 patients had fasting hypoglycemia. For the mice, GAG in the lysosomes nearly disappeared and glycogen particles in the cytoplasm were restored to the normal range in group 4. CONCLUSION: Glucose metabolism in patients with MPS II appeared to function well despite hepatocytic GAG accumulation and hypothetical glycogen depletion. A higher dose of IdS infusion in MPS II mice led to disappearance of lysosomal GAG and restoration of glycogen to the cytoplasm of hepatocytes.
Animals ; Blood Glucose/analysis ; Enzyme Replacement Therapy/methods ; Glycogen/*analysis ; Glycosaminoglycans/*analysis ; Hepatocytes/chemistry/*enzymology ; Humans ; Hypoglycemia/enzymology/physiopathology ; Iduronate Sulfatase/genetics/*physiology ; Liver/ultrastructure ; Mice ; Mice, Knockout ; Microscopy, Electron ; Mucopolysaccharidosis II/blood/enzymology/physiopathology

OBJECTIVEMucopolysaccharidosis type II (MPSII) is a lethal, X-linked recessive disorder caused by mutation of iduronate-2-sulfatase (IDS) gene. Up to now there is no really effective treatment for this disorder, therefore it is important to provide an accurate genetic diagnosis and prenatal diagnosis for the MPSII families. In this study, we identify the pathogenic mutation in a Chinese family with MPSII.

METHODThe 8 years old male proband from a Chinese family was clinically diagnosed with MPSII. There are other 4 patients with similar phenotypes in the family who died at 9, 11, 7 and 10 years of age, respectively. Mutation analysis was carried out by polymerase chain reaction and direct sequencing of all exons and exon/intron boundaries of IDS gene. Denaturing high performance liquid chromatography (DHPLC) analysis was performed to screen the unknown variations of IDS gene in 100 unrelated control males.

RESULTTwo allelic variants of exon 5 (c.684A > G) and exon 6 (c.851C > T) and a nonsense mutation of exon 7 (c.892C > T) were detected in IDS gene of the proband. Heterozygous mutations c.684A > G, c.851C > T and c.892C > T were detected in both proband's mother and maternal grandmother. The unknown variations of c.684A > G and c.851C > T were not found in the 100 unrelated control males. The male fetus (IV11) inherited the same mutation of IDS gene as the proband.

CONCLUSIONMutation c.892C > T of IDS gene causes MPSII in this family and prenatal diagnosis in one affected fetus was achieved.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Child ; DNA Mutational Analysis ; Family ; Female ; Humans ; Iduronate Sulfatase ; genetics ; Male ; Middle Aged ; Mucopolysaccharidosis II ; diagnosis ; genetics ; Mutation ; Phenotype ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo identify the mutations of iduronate-2-sulfatase (IDS) gene, to reveal its mutation features, and to establish a basis for genetic counseling and prenatal gene diagnosis of Hunter syndrome.

METHODSUrine glycosaminoglycans (GAGs) assay, PCR and DNA sequencing were performed to detect mutation of IDS gene of the patient and his parents.

RESULTSThe result showed that the patient was: DS(++), HS(++), KS(-), CS(-), and that both of his parents were negative. A frame-shift deletion mutation (1062 del 16) was identified in exon 7 of the patient's IDS gene. His parents' genotypes were normal.

CONCLUSIONThe patient's mutation was not inherited by his parents but a novel one. The mutation probably altered the primary structure and tertiary structure of IDS enzyme protein remarkably and lowered the activity of IDS enzyme greatly. Therefore it is supposed to be the direct cause of the disorder.

Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child, Preschool ; Female ; Glycoproteins ; genetics ; urine ; Humans ; Male ; Mucopolysaccharidosis II ; enzymology ; genetics ; urine ; Mutation ; genetics

OBJECTIVEMutations of the iduronate-2-sulfatase (IDS) gene is the ultimate cause of Hunter syndrome. Clarification of the nature of mutations will create a necessary premise for prenatal gene diagnosis. A mucopolysaccharidosis (MPS) type II patient and his parents from an ethnic minority in Yunnan province were studied to identify their possible mutation in IDS gene to establish the basis for prenatal gene diagnosis.

METHODSThe patient was a boy, 6 years and 10 months old. Urine glycosaminoglycans (GAGs) assay was used for preliminary diagnosis of the patient and his parents with the disease. The three related persons' DNA was extracted and the concentration and purity of the DNA were measured after the urine test results confirmed the diagnosis. Polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) analysis was performed to detect the position of the mutation around the hot spots of mutation in exon 9, 3, 8 of the IDS gene. DNA bidirectional direct sequencing was applied to analyze the mutation detected by PCR-DHPLC.

RESULTSThe results of GAGs test showed that in the child with MPS, dermatan sulfate (DS) was positive (+++), heparan sulfate (HS) (+++), chondroitin sulfate (CS) and keratan sulfate (KS) were negative (-); while in his parents none of DS, HS, CS and KS was positive. Abnormal peaks in exon 9 of IDS gene shown by PCR-DHPLC were found in the patient. His mother had heterozygotic peaks. A new frame-mutation (1343-TT) in exon 9 of IDS gene of this patient was confirmed by DNA sequencing. The position where mutation occurred was inside codon 407 (TTT), that means two "T" deleted at position 1343 base pair (1343-TT) in cDNA of the IDS gene, caused a new frame-mutation. It caused elongation of the amino acid chain to a terminal codon TGA at position 429. Thus the peptide chain was shortened from 550 to 428 amino acids. The patient is a hemizygote of the mutation and his mother is a heterozygote.

CONCLUSIONA new frame-mutation (1343-TT) on the IDS gene was identified in this study. The patient is a hemizygote and his mother is a heterozygote. The mutation (1343-TT) resulted in loss of 122 amino acids, which probably caused seriously decreased enzyme activity of IDS, and the authors speculate that this mutation may be the pathological basis of the disease. So, if the mother becomes pregnant again, a prenatal gene diagnostic test for the same mutation should be performed. Furthermore, PCR-DHPLC followed by DNA sequencing are effective methods for diagnosis, including prenatal diagnosis of MPS II.

Amino Acid Sequence ; Asian Continental Ancestry Group ; Base Sequence ; Child ; China ; Chromatography, High Pressure Liquid ; Genotype ; Humans ; Iduronate Sulfatase ; genetics ; Male ; Molecular Sequence Data ; Mucopolysaccharidosis II ; diagnosis ; genetics ; Mutation ; Reverse Transcriptase Polymerase Chain Reaction

Child, Preschool ; Humans ; Male ; Mucopolysaccharidosis II ; diagnosis ; genetics ; therapy ; Siblings

OBJECTIVETo identify the mutations of iduronate-2-sulfatase (IDS) gene, and to establish a basis of prenatal gene diagnosis of Hunter syndrome.

METHODSUrine glycosaminoglycan (GAG) assay was used to preliminary diagnosis of mucopolysaccharidosis. PCR-denaturing high-performance liquidchromatograptly (PCR-DHPLC) analysis was performed to detect the mutation in exons 9, 3, 8 of the IDS gene. DNA sequencing was applied to analyze the mutation detected by PCR-DHPLC.

RESULTSAbnormal peaks were found by PCR-DHPLC. A new frame-mutation (1569+TT) in exon 9 of IDS gene was identified by DNA sequencing. Two "T"q inserted in position 1569 base pair (1569+TT) caused a substitution of codon 482 (TTA, leucine) to 482 (TTT, phenylalanine). The "TT" insertion results in the decrease of amino acids from 550 to 482. The patient is a hemizygote and his mother is a heterozygote.

CONCLUSIONA new frame-shift mutation of IDS gene is found to report. The mutation (1569+TT) results in 68 amino acids lost. Probably it causes the enzyme activity seriously dropped down and being pathologically the basis of disease.

Child, Preschool ; Chromatography, High Pressure Liquid ; DNA Mutational Analysis ; Humans ; Iduronate Sulfatase ; genetics ; Male ; Molecular Sequence Data ; Mucopolysaccharidoses ; genetics ; Mucopolysaccharidosis II ; enzymology ; genetics ; Mutation