Background: Cerebral hypoperfusion caused by large-vessel stenosis is an important risk factor for ischemic stroke and vascular cognitive impairment. In vitro, animal and clinic studies demonstrated that DL-3-n-butylphthalide (NBP) can improve the collateral circulation and the cerebral perfusion. In this trial, the benefit of NBP to ameliorate the chronic cerebral hypoperfusion resulting from unilateral internal carotid system stenosis will be explored. Methods: This trial is a randomized, double-blind, placebo-controlled, multicenter clinical study. A total 480 subjects with ≥70% stenosis or occlusion in unilateral internal carotid artery system, cerebral hypoperfusion in the ipsilateral middle cerebral artery (MCA) territory, and no transient ischemic attacks (TIA) or ischemic strokes within 2 weeks will be enrolled in China. Patients will be assigned in a 1:1 ratio to NBP and placebo groups. Patients in NBP or placebo group received 200 mg or 20 mg of NBP capsules three times daily for 4 weeks respectively. The cerebral perfusion will be assessed again after 12 weeks. The primary efficacy outcome is the proportion of patients with cerebral blood flow (CBF) amelioration, stabilization and deterioration after treatment. Conclusions: This trial will provide a high-level of evidence for NBP to treat the cerebral hypoperfusion, and a novel strategy to improve the cerebral hemodynamic impairment due to large intracranial and extracranial atherosclerotic stenosis in the surgical high-risk patients, especially in the aged and Asians. Trial registration: This trial is registered as ChiCTR2100053112 on November 12th, 2021.

Purpose/aim of the study: Cerebrovascular reactivity (CVR) reflects the vasodilatory reserve of cerebral resistance vessels, which is an important marker for assessing cerebrovascular disease. The present study is to investigate whether CVR impairment increases adverse long-term outcome risk of patients with 50% symptomatic unilateral middle cerebral artery (MCA) stenosis (ischemic stroke (IS) or transient ischemic attack (TIA)).Material and methods: Digital subtraction angiography (DSA) was used to assess the degree of stenosis, and perfusion CT and 5% CO2 inhalation were adopted to evaluate CVR. Patients with 50% symptomatic unilateral MCA stenosis were assigned to non-CVR impairment group and CVR impairment group according to CVR status. The long-term follow-up endpoint was composite of any IS ( in the territory of the studied MCA) or death within 12 months.Results: Seventy-three patients with 50% symptomatic unilateral MCA stenosis, involving 31 non-CVR impairment cases and 42 CVR impairment cases, were included in the present study. Finally, IS occurred in six CVR impairment patients, and no endpoint happened in the non-CVR impairment group. Therefore, the annual rate of IS was 14.29% in the CVR impairment group and 0% in the non-CVR impairment group (P = 0.035). Besides, further Kaplan-Meier analysis found CVR impairment was closely associated with the IS risk (Kaplan-Meier Log-rank 4.719, P = 0.030).Conclusions: Our results showed that for patients with 50% symptomatic unilateral MCA stenosis, there was significant difference between non-CVR impairment cases and CVR impairment cases in the annual rate of IS. It suggests that CVR impairment increases the risk of adverse long-term outcomes.

Purpose/Aim of the study: Cerebrovascular reactivity (CVR) is an important marker for assessing cerebrovascular disease. This study assessed the CVR by perfusion computed tomography (CT) and CO2 inhalation tests in patients with unilateral middle cerebral artery (MCA) stenosis disease. Materials and Methods: Thirty-one patients with unilateral MCA stenosis disease diagnosed by digital subtraction angiography were studied. Patients were divided into two groups according to the degree of stenosis: severe and moderate. The regional cerebral blood flow (CBF) before and after CO2 inhalation was determined by perfusion CT. Regional CVR values were obtained by the following formula: increase (%) = (post-CBF) -(pre-CBF)/(pre-CBF) x 100%. Results: No significant differences in the mean CBF in the MCA stenosis region were found between the affected and contralateral sides before the CO2 inhalation test; after the test, CBF was more significantly decreased on the affected side than on the contralateral side. The changes in CBF on the affected side were categorized into three types: increased CBF (17 cases), decreased CBF (12 cases) and no change in CBF (2 cases). The rate of CVR impairment among severe stenosis patients (13/19) was higher than that among moderate stenosis patients (3/12). CVR was significantly correlated with the degree of stenosis (r = 0.423, P = 0.018). Conclusion: CVR impairment was found in approximately half of patients with unilateral MCA stenosis. Along with an increase in the degree of stenosis, patients with unilateral MCA stenosis were more likely to exhibit CVR impairment. It is important to assess the CVR in patients with unilateral MCA stenosis, especially those with severe stenosis.

Mucolipidosis II and III alpha/beta are autosomal recessive diseases caused by mutations in the GNPTAB gene which encodes the α and β subunits of the N-acetylglucosamine-1-phosphotransferase. Clinically, mucolipidosis II (MLII) is characterized by severe developmental delay, coarse facial features, skeletal deformities, and other systemic involvement. In contrast, MLIII alpha/beta is a much milder disorder, the symptoms of which include progressive joint stiffness, short stature, and scoliosis. To study the relationship between the genotypes and phenotypes of the MLII and MLIII alpha/beta patients, we analyzed the GNPTAB gene in 16 Chinese MLII and MLIII alpha/beta patients. We collected and analyzed the patients' available clinical data and all showed clinical features typical of MLII or MLIII alpha/beta. Moreover, the activity of several lysosomal enzymes was measured in the plasma and finally the GNPTAB gene was sequenced. We detected 30 mutant alleles out of 32 alleles in our patients. These include 10 new mutations (c.99delC, c.118-1G>A, c.523_524delAAinsG, c.1212C>G, c.2213C>A, c.2345C>T, c.2356C>T, c.2455G>T, c.2821dupA, and c.3136-2A>G) and 5 previously reported mutations (c.1071G>A, c.1090C>T, c.2715+1G>A, c.2550_2554delGAAA, and c.3613C>T). The most frequent mutation was the splicing mutation c.2715+1G>A, which accounted for 28% of the mutations. The majority of the mutations reported in the Chinese patients (57%) were located on exon 13 or in its intronic flanking regions.

目的 探讨黏多糖贮积症Ⅱ型非损伤性产前诊断途径. 方法 测定36例孕妇孕前、孕早期和孕中期外周血浆中艾杜糖-2-硫酸酯酶(IDS)活性变化趋势,同时,测定胎儿绒毛组织或经培养羊水细胞中IDS酶活性,并提取胎儿DNA,进行胎儿性别鉴定和IDS基因分析. 结果 有创产前诊断检出19例正常胎儿(7例男性不受累胎儿、12例女性非携带者胎儿)、7例男性受累胎儿、9例女性携带者胎儿和1例双胎(一男一女,不受累);正常胎儿孕母在孕前、孕早、中期血浆中IDS的活性分别为283.4±81.6、470.5±89.4、507.9±81.0 nmol/4 h· ml(男性不受累胎儿)和306.0±85.5、455.8±129.4、513.3±157.6 nmol/4 h·ml(女性非携带者胎儿),均显著高于男性受累胎儿和女性携带者胎儿孕母同期血浆IDS活性(分别为160.5±47.5、145.8±36.8、144.9±45.8 nmol/4 h·ml和214.9±74.8、327.6±133.4、375.3±120.4 nmol/4 h·ml)(P＜0.05);正常胎儿和女性携带者胎儿孕母血浆IDS活性随着孕周的增加持续升高(P＜0.05),但女性携带者胎儿组升高的幅度较正常胎儿组小;当为男性受累胎儿时,孕妇血浆IDS活性早期即显示低于孕前,且随着孕周的增加,酶活性持续降低. 结论 孕妇外周血中IDS活性测定可用于黏多糖贮积症Ⅱ型的非损伤性产前诊断.

Objective To compare the diagnostic effectiveness of methylation-specific PCR ( MS-PCR ) and methylation-specific multiplex ligation-dependent probe amplification ( MS-MLPA ) in clinical suspected Prader-Willi syndrome (PWS).Methods One hundred and two participants (57 males and 45 females) who visited Peking Union Medical College Hospital in the period from October 2005 to February 2014 were included in this retrospective study .Among the 102 participants , 16 were normal controls , 2 PWS cases confirmed by fluores-cence in situ hybridization or high resolutin banding were positive controls , and 84 were suspected PWS cases . Genomic DNA was extracted for MS-PCR and MS-MLPA, based on which diagnoses were made and genetic types distinguished .Chi-squared test was used to compare the sensitivity , specificity , and accuracy of the two meth-ods .Results MS-PCR results showed that all normal controls and positive controls were conform to their pheno -types .Thirty-nine in the 84 suspected patients were shown to be PWS , and the other 45 to be normal .MS-MLPA showed that in the 86 non-normal participants ( positive control and suspected cases ) , 29 had paternal deletions , 9 had maternal uniparental disomy ( mUPD) , 47 were normal;and the assay failed to produce effective result in 1 case due to the overlong DNA storage time .Two participants were diagnosed as PWS cases by MS-PCR but nor-mal by MS-MLPA.The diagnosis of PWS was ruled out by repeat MS-PCR after doubling DNA dosage .Combined with clinical manifestations , 39 participants were definitively diagnosed as PWS , the other 63 were not PWS .The false-positive rate of MS-PCR was 3.17% (2/63).The sensitivity, specificity, and accuracy of MS-PCR were 100%, 96.83%, and 98.03%, respectively; while those indicators of MS-MLPA were 97.43%, 100%, and 99.02%, respectively , showing no significant difference ( all P>0.05 ) .Conclusions Both MS-PCR and MS-MLPA have high sensitivity , specificity , and accuracy , thus are effective for PWS diagnosis .MS-MLPA can dis-tinguish paternal deletion and mUPD .Enough dose of DNA is requisite in MS-PCR to avoid false-positive results . Freshness of DNA samples is essential in MS-MLPA, which also needs more strict performance standards .We suggest a combination of MS-PCR and MS-MLPA in diagnosing PWS to ensure the accuracy of the result .

Based on the Systematic Layout Planning theory and the analysis of transfer stations’ technological processes, a layout optimization model for solid waste transfer and disposal stations was made. The operating units’ layout of the solid waste transfer and disposal stations was simulated and optimized using the genetic algorithm, which could achieve reasonable technological processes, the smallest floor space and the lowest construction cost. The simulation result can also direct the initial engineering design and can also provide reference for similar engineering design methods.

Compression box is a major part of MSW transfer station's compression unit. Box structure's design should meet load requirement and achieve weight optimization. Based on the analysis of the box structure, a load distribution model of compressed MSW in the compression box was made. Using SolidWorks and ANSYS to analyze the model, the analysis result can provide scientific basis for the optimization design of the MSW transfer station's compression boxes.

A systematic, global and integration concept is applied upon garbage disposal problem caused by the substantial increase of garbage in China's cities and towns to promote the coordinated development of garbage stations. A kind of echelon pattern of urban circle solid waste disposal is put forward as well as five key technologies which are essential to be used in the pattern. The echelon pattern can provide the technical foundation for urban-rural garbage treatment station construction and assessment and help policy makers to make sound decisions in improving the comprehensive efficiency of urban circle solid waste disposal.

Based on the theory of QFD and a systematic description of the echelon pattern of urban circle solid waste disposal, a specific waterfall decomposition model for integrated design of the echelon pattern is brought forward, which is made of four houses of quality. The first house of the waterfall decomposition model- the HOQ of facilities planning for urban circle solid waste disposal is set as an example. From the angle of customer requirements, the importance of different kind of customer requirements is calculated quantitatively, using the method of Analytic Hierarchy Process. By analyzing the internal relationship of the echelon pattern, it's concluded that the site selection of solid waste disposal points, stations and fields, and efficiency of solid waste disposal are the most important problems of the design for the echelon pattern of urban circle solid waste disposal. This work provides academic basis for the integrated design of the echelon pattern of urban circle solid waste disposal.

BACKGROUND:Mucolipidosis type III gamma (MLIII gamma) is an autosomal recessive disease caused by a mutation in the GNPTG gene, which encodes the γ subunit of the N-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase). This protein plays a key role in the transport of lysosomal hydrolases to the lysosome. METHODS:Three Chinese children with typical skeletal abnormalities of MLIII were identified, who were from unrelated consanguineous families. After obtaining informed consent, genomic DNA was isolated from the patients and their parents. Direct sequencing of the GNPTG and GNPTAB genes was performed using standard PCR reactions. RESULTS:The three probands showed clinical features typical of MLIII gamma, such as joint stiffness and vertebral scoliosis without coarsened facial features. Mutation analysis of the GNPTG gene showed that three novel mutations were identified, two in exon seven [c.425G>A (p.Cys142Val)] and [c.515dupC (p.His172Profs27X)], and one in exon eight [c.609+1G>C]. Their parents were determined to be heterozygous carriers when compared to the reference sequence in GenBank on NCBI. CONCLUSIONS:Mutation of the GNPTG gene is the cause of MLIII gamma in our patients. Our findings expand the mutation spectrum of the GNPTG gene and extend the knowledge of the phenotype-genotype correlation of the disease.

OBJECTIVE:Multiple sulfatase deficiency is a rare autosomal recessively inherited lysosomal storage disorder characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The aim of this study was to explore the clinical manifestations, enzyme activities and SUMF1 gene mutations in two Chinese patients with multiple sulfatase deficiency.METHOD:One boy and one girl from two families were studied. Both patients presented with mental retardation, mild coarse facial features, a neurodegenerative course of disease with loss of sensory and motor function after 2 years of age, ichthyosis and skeletal abnormalities (kyphosis or/and scoliosis). Clinical characteristics indicate multiple sulfatase deficiency.Sulfatases activities in blood leucocytes, plasma or cultured fibroblast of the patients were measured.Genomic DNAs were extracted from peripheral blood leukocytes from the patients and their parents. All SUMF1 gene exons and intron-exon boundaries were amplified by PCR and subjected for direct sequencing.RESULT:In case 1, five sulfatases activities of blood leucocytes and four sulfatases of cultured skin-fibroblasts were analyzed.In case 2, three sulfatases activities of blood leucocytes were tested.Significantly decreased sulfatases activities confirmed the diagnosis of multiple sulfatase deficiency.On SUMF1 gene, c.793_794 insATG (p. P265X)/ c.1045C>T (p.R349W) in case 1 and c.451A>G (p.K151E)/ c.1046G>C (p.R349Q) in case 2 were detected, respectively. Three novel mutations c.793_794insAGT, c.1046G>C and c.451A>G were identified.CONCLUSIONS:Multiple sulfatase deficiency usually results in multi-organ damage, especially neurologic, skeletal and skin.Sulfatases assay and SUMF1 gene analysis are necessary for the diagnosis. Two Chinese cases with multiple sulfatase deficiency were firstly reported. Three novel mutations were found.It should be considered that the mutation profile of SUMF1 gene in Chinese patients is different from other populations.

Introduction: Mucopolysaccharidosis (MPS) type VI (Maroteaux-Lamy syndrome) is a clinically heterogeneous lysosomal storage disorder. It presents significant diagnostic and treatment challenges due to the rarity of the disease and complexity of the phenotype. As information about MPS VI in Asia-Pacific countries is limited, a survey was conducted to assess current practices for diagnosis and management of MPS VI in this region. The participants were selected based on their experience in diagnosing and managing MPS patients.Methods: The survey comprised 29 structured quantitative or qualitative questions. Follow-up consultations were undertaken to discuss the data further.Results: Thirteen physicians from eight countries or regions (Australia, China, Hong Kong, Japan, Malaysia, Philippines, Taiwan and Thailand) were surveyed. At the time of the survey twenty-two patients with MPS VI were directly treated by the respondents and most (similar to 80%) had rapidly progressing disease. A wide range of medical specialists are involved in managing patients with MPS VI, the most common being orthopedic surgeons, pediatricians and geneticists. The availability/accessibility of diagnostic tools, therapies and national insurance coverage vary greatly across the countries/regions and, in some cases, between different regions within the same country. Currently, there are national MPS management groups in Australia and Japan. Australia, Taiwan and Hong Kong have local guidelines for managing MPS and local MPS registries are available in Australia, Taiwan, and Japan.Conclusions: This survey highlights differences in the diagnosis and management of MPS VI between Asia-Pacific countries/regions. Important barriers to advancing the identification, understanding and treatment of MPS VI include the paucity of epidemiological information, limited access to laboratory diagnostics and therapies, low disease awareness, and a lack of monitoring and treatment guidelines. There is a clear need to facilitate communications between physicians and establish regional or national disease registries, a multidisciplinary referral network, and a centralized diagnostic and management framework. (C) 2012 Elsevier Inc. All rights reserved.

OBJECTIVE:Mucopolysaccharidosis type I (MPS I; MIM# 252800) is an autosomal recessive disease that results from the deficiency in the lysosomal enzyme α-L-iduronidase(IDUA). IDUA is one of the enzymes involved in degradation of glycosaminoglycans heparan sulphate and dermatan sulphate. The deficiency of IDUA leads to widespread accumulation of partially degraded mucopolysaccharides inside lysosomes, resulting in progressive cellular and multiorgan dysfunction. Up to now there is no definitely effective treatment for this disorder, therefore it is important to provide an accurate genetic diagnosis and prenatal diagnosis for the MPSI families. This study was conducted to detect IDUA gene mutation in patients with MPSIand make a definite diagnosis of homozygote or heterozygote and make first trimester prenatal diagnosis.METHOD:The 2 male probands included in this study were diagnosed as MPSI patients in Peking Union Medical College Hospital, case 1 was 2 years old and case 2 was 5 years old. Genomic DNA was extracted from leucocytes in the 2 patients and 2 mothers' cultured amniocytes. IDUA gene DNA sequence was amplified by polymerase chain reaction (PCR) and the PCR products were sequenced directly. Novel mutations were analyzed in 100 normal chromosomes.RESULT:The genotype of case 1 was p.L238R/c.883InsC, while of case 2 was c.531InsT/p.L346R. The fetal case 1 did not inherit the same pathogenic mutations as proband 1, the activity of the IDUA in amniocytes was 9.0 nmol/(h·mg pr). The fetal case 2 inherited the same pathogenic mutations with the proband, the genotype of fetal 2 was c.531InsT/p.L346R, the activity of the IDUA in amniocytes was 0.5 nmol/(h·mg pr).CONCLUSION:Of the 4 mutations found in 2 MPS I patients, p. L238R, c.883InsC, c.531InsT were novel. The fetal case 1 was diagnosed as normal fetus while the fetus 2 was diagnosed as affected. The results of the two kinds of prenatal diagnostic methods were correspondent with each other.

OBJECTIVE:Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disease resulting from the deficiency in the lysosomal enzyme alpha-L-iduronidase (IDUA). The present study was conducted to identify IDUA gene mutations in attenuated (MPS I H/S and MPS I S) patients with MPS I in northern China.METHODS:Fourteen exons with adjacent intronic sequences of the IDUA gene in 11 MPS I patients were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced directly and origin analysis was conducted.RESULTS:Seven mutations were detected in the 11 MPS I patients, i.e., c.236 C to T (p. A79V), c.266 G to A (p.R89Q), c.265 C to T (p.R89W), c.532G to A (p.E178K), c.589G to A (p.G197S), c.1037T to G (p.L346R), and c.1877 G to A (p.W626X). All of them were known mutations. Six patients were homozygotes and 1 was heterozygote with nonsense mutation. In addition, 9 reported single nucleotide polymorphism (SNP) were detected, i.e., p.A8, p.A20, p.H33Q, p.R105Q, p.A314, p. A361T, p.T388, p.T410 and p.V454I.CONCLUSION:The mutation spectrum of the IDUA gene in attenuated MPS I Chinese patients may be different from that in patients from other countries.

BACKGROUND:Niemann-Pick disease type C (NP-C), derived from mutation of the NPC1 or NPC2 gene, is one of the recessive lysosomal lipid storage disorders that are difficult to diagnose and treat. Since NP-C has been rarely reported in China, we reviewed 7 patients with NP-C.METHODS:The 7 patients had been diagnosed with NP-C from 2007 to 2010 at our department and their laboratory and clinical data were analyzed.RESULTS:The 7 patients, 5 males and 2 females, included 4 patients of late infantile subtype and 3 patients of juvenile subtype, in which patients 2 and 3 were siblings. Their clinical symptoms occurred from 4 to 10 years of age, exhibiting as progressive cognitive and language impairment as well as motor retrogression. Six patients were caught by focal or generalized seizures from 1 to 4 years after the onset of the disease. Vertical supranuclear gaze palsy, dysarthria, dysphagia, internal rotation and adduction of bilateral hands and splenomegaly occurred following the progress of clinical symptoms. Five patients had laughter-cataplexy. MRI showed mild brain atrophy in 6 patients. Reduction of total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol occurred in 6 patients. Sea-blue cells and Niemann-Pick cells were found in bone marrow smears. The activity of acid sphingomyelin enzyme was normal or only slightly lower. Supporting or symptomatic treatment improved common clinical symptoms.CONCLUSIONS:NP-C is a rare autosomal recessive inherited lysosomal storage disease that affects the intellectual development of children and may lead to dementia, vegetative state or death. Clinical features of this disease include vertical supranuclear gaze palsy, seizures and cataplexy. Laboratory features include abnormal plasma cholesterol level, and sea-blue cells and Niemann-Pick cells in bone marrow smears. The treatments of the disease include supporting or symptomatic administration.

OBJECTIVE:Wolcott-Rallison syndrome (WRS) is a rare autosomal recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple epiphyseal dysplasia and growth retardation, and other variable multisystem clinical manifestations. Here we describe a Chinese boy affected by WRS. Genetic testing of his EIF2AK3 gene was performed in order to elucidate molecular variations and subsequently to provide credible genetic counseling for prenatal diagnosis in his family.METHOD:Based on analysis of a nine-year-old boy's clinical symptoms associated with biochemical examination and imaging, the diagnosis of WRS was therefore made. Genomic DNAs were extracted from peripheral blood leukocytes from the boy and his parents with their informed consent for genetic studies. All EIF2AK3 exons and intron-exon boundaries were amplified by Touch-down polymerase chain reaction (Touch-down PCR) and sequenced.RESULT:Direct sequencing of PCR products revealed the presence of a heterozygous T insertion (c.1408_1409insT) in exon 8 of the EIF2AK3 gene leading to frameshifting and termination, and another heterozygous T to A exchange (c.1596T > A) in exon 9 of the EIF2AK3 gene resulting in nonsense C532X mutation.CONCLUSION:Combining mutation screening of EIF2AK3 gene with clinical manifestations and effective examination may provide a reliable diagnostic method for patients. In this research, two novel mutations identified in the Chinese boy locate in the catalytic domain of the EIF2AK3 gene, disrupting the ability of autophosphorylation, leading to the truncated proteins that are unable to phosphorylate the natural substrate, which are responsible for the phenotype of Wolcott-Rallison syndrome.

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease that results from the deficiency of α-l-iduronidase and is transmitted in an autosomally recessive manner. This report describes the first systematic screening for mutations in Chinese MPS I patients from mainland China, wherein we have summarized the phenotype/genotype correlation of the individuals in Chinese MPS I patients. Mutational analyses were performed in 57 unrelated Chinese MPS I patients. Overall, 105 mutant alleles were identified from a set of 41 different mutations. Notably, of these 41 mutations, 27 were novel mutations that consisted of 8 splicing mutations (c.1-2C>G, c.296+4G>A, c.300-1G>C, c.792+1G>C, c.973-4G>A, c.1189+5G>T, c.1402+1G>T and c.1402+2T>G), 1 nonsense mutation (p.W41X), 1 insertion (c.668-670ins GCG), 5 duplications (c.531dupT, c.657dupG, c.883dupC, c.1147dupG and c.1225dupG), 3 deletions (c.349delT, c.1593delG and c.1244-1271del27),1 nucleotide substitution c.2T>C and 8 missense mutations (p.H33P,p.F52L, p.G168V,p.T179R,p. E182D, p.L237R, p.L238R and p.L421P). The missense mutations p.A79V and p.L346R, which accounted for 16.7% (19/114) and 12.3% (14/114) respectively, were the common mutations in Chinese patients but were rare in the mutational profiles reported for other populations. These results indicate that Chinese MPS I patients may have a different mutational spectrum compared to those of other populations. Moreover, for the first time in China, molecular genetic methods were used for prenatal diagnosis of six cases in five families.

Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is a lysosomal storage disease caused by deficiency of N-acetylgalactosamine-6-sulfatase (GALNS) and transmitted as an autosomal recessive trait. This is the first systematic mutation screen in Chinese MPS IVA patients. Mutation detections in 24 unrelated Chinese MPS IVA patients were performed by PCR and direct sequencing of exons or the mRNA of GALNS. A total of 42 mutant alleles were identified, belonging to 27 different mutations. Out of the 27 mutations, 16 were novel, including 2 splicing mutations (c.567-1G>T and c.634-1G>A), 2 nonsense mutations (p.W325X and p.Q422X) and 12 missense mutations (p.T88I, p.H142R, p.P163H, p.G168L, p.H236D, p.N289S, p.T312A, p.G316V, p.A324E, p.L366P, p.Q422K and p.F452L). p.G340D was found to be a common mutation in the Chinese MPS IVA patients, accounting for 16.7% of the total number of mutant alleles. The results show that the mutations in Chinese MPS IVA patients are also family specific but have a different mutation spectrum as compared to those of other populations.

OBJECTIVE:To investigate the clinical manifestations and to characterize mutations of the GLA gene in Chinese patients with Fabry disease so to enhance the diagnosis of Fabry disease.METHODS:Sixteen Chinese affected males (from 16 unrelated families) with the classic phenotype of Fabry disease were investigated. The patients were diagnosed by a deficiency of alpha-galactosidase A (alpha-Gal A) activity. All seven exons and the neighboring intronic sequences of GLA gene were analyzed by PCR amplification and automated sequencing.RESULTS:A total of 14 mutations were identified including 12 single-base substitutions (11 missense and 1 nonsense mutations), 1 small deletion and 1 splicing mutation. Eight novel mutations (c.119 C > A, c.275 A > T, c.520T > C, c.547G > C, c.647A > G, c.929T > G, c.1045T > A, IVS1-1G > A) were identified. The novel mutations were not tested by RFLP on 100 GLA alleles in Chinese population, and were highly conservative in mammalian species.CONCLUSION:Fabry disease is often misdiagnosed in China. There is no hot spot for mutations in Chinese patients. GLA gene mutation analysis is a reliable method to diagnosis for Fabry disease.