Achromatopsia caused by novel missense mutations in the CNGA3 gene

AIMTo identify the genetic defects in a Chinese family with achromatopsia.METHODSA 2.5-year-old boy, who displayed nystagmus, photophobia, and hyperopia since early infancy, was clinically evaluated. To further confirm and localize the causative mutations in this family, targeted region capture and next-generation sequencing of candidate genes, such as CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H were performed using a custom-made capture array.RESULTSSlit-lamp examination showed no specific findings in the anterior segments. The optic discs and maculae were normal on fundoscopy. The unaffected family members reported no ocular complaints. Clinical signs and symptoms were consistent with a clinical impression of autosomal recessive achromatopsia. The results of sequence analysis revealed two novel missense mutations in CNGA3, c.633T>A (p.D211E) and c.1006G>T (p.V336F), with an autosomal recessive mode of inheritance.CONCLUSIONGenetic analysis of a Chinese family confirmed the clinical diagnosis of achromatopsia. Two novel mutations were identified in CNGA3, which extended the mutation spectrum of this disorder.

Functional analysis of missense mutations in GLI2 and GLI3 involved in congenital heart disease

Objective:In this study,we aimed to explore the biological functions of 10 rare case-specific missense mutations in GLI2 and 4 in GLI3,which were previously screened in a cohort of 412 patients with congenital heart disease(CHD)and 213 normal controls from Shandong Province,China.Methods:A dual-luciferase reporter assay was used to assess the effects of these mutations in GLI2 and GLI3 on the activity of the sonic Hedgehog signaling pathway in HEK293T cells.Differences in protein levels between mutant and wild-type GLI2 and GLI3 were detected in HEK293T cells using Western blotting.Results:The dual-luciferase reporter assay showed that compared to the wild-type GLI2 protein,p.A1113V significantly increased activation of the sonic Hedgehog signaling pathway,whereas p.H78P and p.I1451S did not have a significant effect.The other mutations largely reduced the activation effect.Compared with the wild-type GLI3 protein,only p.A286V,among the four mutations,significantly reduced the activation effect on the SHH signaling pathway.Western blotting data showed reduced expression of GLI2 p.G716V,GLI2 p.K736N,GLI2 p.I1451S,and GLI3 p.A286V,whereas the remaining mutations had no significant effects.Conclusion:The mutations GLI2 c.2147G>T(p.G716V),GLI2 c.2208G>C(p.K736N),and GLI3 c.857C>T(p.A286V)involved in CHD affect the regulation of the sonic Hedgehog signaling pathway;thus,these rare missense mutations in GLI2 and GLI3 might increase the risk of CHD.

Three novel missense germline mutations in different exons of MSH6 gene in Chinese hereditary non-polyposis colorectal cancer families

AIM: To investigate the germline mutations of MSH6 gene in probands of Chinese hereditary non-polyposis colorectal cancer (HNPCC) families fulfilling different clinical criteria. METHODS: Germline mutations of MSH6 gene were detected by PCR-based DNA sequencing in 39 unrelated HNPCC probands fulfilling different clinical criteria in which MSH2 and MLH1 mutations were excluded. To further investigate the pathological effects of detected missense mutations, we analyzed the above related MSH6 exons using PCR-based sequencing in 137 healthy persons with no family history. The clinicopathological features were collected from the Archive Library of Cancer Hospital, Fudan University and analyzed. RESULTS: Four germline missense mutations distributed in the 4th, 6th and 9th exons were observed. Of them, three were not found in international HNPCC databases and did not occur in 137 healthy controls, indicating that they were novel missense mutations. The remaining mutation which is consistent with the case H14 at c.3488A>T of exon 6 of MSH6 gene was also found in the controls, the rate was approximately 3.65% (5/137) and the type of mutation was not found in the international HNPCC mutational and SNP databases, suggesting that this missense mutation was a new SNP unreported up to date. CONCLUSION: Three novel missense mutations and a new SNP observed in the probands of Chinese HNPCC families, may play an important role in the development of HNPCC.

A rare missense PAX6 mutation causes atypical aniridia in a three-generation Chinese family

●AIM:To investigate the molecular diagnosis of a threegeneration Chinese family affected with aniridia,and further to identify clinically a PAX6 missense mutation in members with atypical aniridia.●METHODS:Eleven family members with and without atypical aniridia were recruited.All family members underwent comprehensive ophthalmic examinations.A combination of whole exome sequencing(WES)and direct Sanger sequencing were performed to uncover the causative mutation.●RESULTS:Among the 11 family members,8 were clinically diagnosed with congenital aniridia(atypical aniridia phenotype).A rare heterozygous mutation c.622C>T(p.Arg208Trp)in exon 8 of PAX6 was identified in all affected family members but not in the unaffected members or in healthy control subjects.●CONCLUSION:A rare missense mutation in the PAX6 gene is found in members of a three-generation Chinese family with congenital atypical aniridia.This result contributes to an increase in the phenotypic spectrum caused by PAX6 missense heterozygous variants and provides useful information for the clinical diagnosis of atypical aniridia,which may also contribute to genetic counselling and family planning.

Computational analysis of deleterious missense mutations in aspartoacylase that cause Canavan's disease

In this work, the most detrimental missense mutations of aspartoacylase that cause Canavan's disease were identified computationally and the substrate binding efficiencies of those missense mutations were analyzed. Out of 30 missense mutations, I-Mutant 2.0, SIFT and PolyPhen programs identified 22 variants that were less stable, deleterious and damaging respectively. Subsequently, modeling of these 22 variants was performed to understand the change in their conformations with respect to the native aspartoacylase by computing their root mean squared deviation (RMSD). Furthermore, the native protein and the 22 mutants were docked with the substrate NAA (N-Acetyl-Aspartic acid) to explain the substrate binding efficiencies of those detrimental missense mutations. Among the 22 mutants, the docking studies identified that 15 mutants caused lower binding affinity for NAA than the native protein. Finally, normal mode analysis determined that the loss of binding affinity of these 15 mutants was caused by altered flexibility in the amino acids that bind to NAA compared with the native protein. Thus, the pre- sent study showed that the majority of the substrate-binding amino acids in those 15 mutants displayed loss of flexibility, which could be the theoretical explanation of decreased binding affinity between the mutant aspartoacylases and NAA.

A computational approach to explore the functional missense mutations in the spindle check point protein Mad1

In this work, the most detrimental missense mutations of Madl protein that cause various types of cancer were identified computationally and the substrate binding efficiencies of those missense mutations were analyzed. Out of 13 missense mutations, I Mutant 2.0, SIFT and PolyPhen programs identified 3 variants that were less stable, deleterious and damaging respectively. Subsequently, modeling of these 3 variants was performed to understand the change in their conformations with respect to the native Madl by computing their root mean squared deviation （RMSD）. Furthermore, the native protein and the 3 mutants were docked with the binding partner Mad2 to explain the substrate binding efficiencies of those detrimental missense mutations. The docking studies identified that all the 3 mutants caused lower binding affinity for Mad2 than the native protein. Finally, normal mode analysis determined that the loss of binding affinity of these 3 mutants was caused by altered flexibility in the amino acids that bind to Mad2 compared with the native protein. Thus, the present study showed that majority of the substrate binding amino acids in those 3 mutants displayed loss of flexibility, which could be the theoretical explanation of decreased binding affinity between the mutant Madl and Mad2.

Functional and structural characterization of missense mutations in PAX6 gene

The PAX6 gene belongs to the Paired box （PAX） family of transcription factors that is tissue specific and required for the differentiation and proliferation of cells in embryonic development. PAX6 regulates the pattern formation in early developmental stages. This function of PAX6 protein enables the successful completion of neurogenesis and oculogenesis in most animals such as mice, Drosophila and some other model organisms including humans. A variation in the sequence of PAX6 gene may alter the function and structure of the protein. Such changes can produce adverse effects on functioning of the PAX6 protein which were clinically observed to occur in a broad range of ocular defects such as aniridia in humans. We employed in silico prediction methods such as SIFT, PolyPhen 2; I mutant 3.0, SNAP, SNPs＆GO, and PHD-SNP to screen the pathogenic missense mutation in PAX6 and DNA binding sites by BindN and BindN ＋. Furthermore, we employed KD4V server to examine the structural and functional modifications that occur in the PAX6 protein as a result of mutation. Based on the results obtained from the in silico prediction methods, we carried out modeling analysis for V53L, I56T, G64V, and I87R to visualize the impact of mutation in structural context.

A novel missense mutation in QRICH2 causes male infertility due to multiple morphological abnormalities of the sperm flagella

Multiple morphological abnormalities of the sperm flagella(MMAF)are characterized by bent,irregular,short,coiled,and absent flagella.MMAF is caused by a variety of genes,some of which have been identified.However,the underlying genetic factors responsible for the majority of MMAF cases are still largely unknown.The glutamine-rich 2(QRICH2)gene plays an essential role in the development of sperm flagella by regulating the expression of essential sperm flagellar biogenesis-associated proteins,and genetic variants of QRICH2 have been identified as the primary cause of MMAF in humans and mice.Here,we recruited a Pakistani consanguineous family to identify the genetic variant causing infertility in patients with MMAF.Whole-exome sequencing and Sanger sequencing were conducted to identify potentially pathogenic variants causing MMAF in infertile patients.Hematoxylin and eosin(HE)staining was performed to analyze sperm morphology.Quantitative polymerase chain reaction,western blot,and immunofluorescence staining analyses were conducted to observe the expression of QRICH2 in spermatozoa.A novel homozygous missense variant(c.4618C>T)in QRICH2 was identified in the affected patients.Morphological analysis of spermatozoa revealed the MMAF phenotype in infertile patients.qPCR revealed a significant reduction in the level of sperm QRICH2 mRNA,and immunofluorescence staining revealed a lack of sperm QRICH2 expression.Additionally,patients harboring a homozygous QRICH2 mutation presented reduced expression of outer dense fiber 2(ODF2)in sperm,whereas sperm expression of A-kinase anchor protein 4(AKAP4)was normal.These findings expand our understanding of the genetic causes of MMAF-associated male infertility and emphasize the importance of genetic counseling.

Identification of a Novel VEGFR-3 Missense Mutation in a Chinese Family with Hereditary Lymphedema Type I

A novel mutation of vascular endothelial growth factor receptor gene （VEGFR-3）, was identified in a four-generation Chinese family with hereditary lymphedema type I （HL-I）. Genetic linkage analysis was performed on the known genetic locus for HL-I with a panel of polymorphic markers, and then mutations were screened out by direct sequencing. By genotyping, the family showed the linkage to HL-I locus on 5q35.3. Mutation screening analysis of the exons encoding the intracellular kinase domains of VEGFR-3, revealed a novel missense mutation D1055V. This mutation cosegregated with the disease phenotype in the family and was not found in 100 normal controls. This finding has expanded the spectrum of the VEGFR-3 gene mutations causing HL-I, and will be useful for further genetic consultation and genetic diagnosis.

MYH7 mutation in a pedigree with familial dilated hypertrophic cardiomyopathy:A case report and review of literature

BACKGROUND Hypertrophic cardiomyopathy(HCM)is one of the most prevalent inherited myocardial disorders and is charac-terized by considerable genetic and phenotypic heterogeneity.A subset of patients with HCM progress to a dilated phase of HCM(DPHCM),which is associated with a poor prognosis;however,the underlying pathogenesis remains inadequately understood.CASE SUMMARY In this study,we present a case involving a pedigree with familial DPHCM and conduct a retrospective review of patients with DPHCM with identified gene mutations.Through panel sequencing targeting the coding regions of 312 genes associated with inherited cardiomyopathy,a heterozygous missense mutation(c.746G>A,p.Arg249Glu)in the MYH7 gene was identified in the proband(III-5).Sanger sequencing subsequently confirmed this pathogenic mutation in three additional family members(II-4,III-4,and IV-3).A total of 26 well-documented patients with DPHCM were identified in the literature.Patients with DPHCM are commonly middle-aged and male.The mean age of patients with DPHCM was 53.43±12.79 years.Heart failure,dyspnoea,and atrial fibrillation were the most prevalent symptoms observed,accompanied by an average left ventricular end-diastolic size of 58.62 mm.CONCLUSION Our findings corroborate the pathogenicity of the MYH7(c.746G>A,p.Arg249Glu)mutation for DPHCM and suggest that the Arg249Gln mutation may be responsible for high mortality.

Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders

Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular,and cellular interactions. Ameloblastin(AMBN, also named "amelin" or "sheathlin") is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta(AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders.We recruited one kindred with autosomal-dominant amelogenesis imperfecta(ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders.

Novel mutations of the Alstr?m syndrome 1 gene in an infant with dilated cardiomyopathy:A case report

BACKGROUND Alstr?m syndrome(AS)is a rare autosomal recessive disease that is generally induced by mutations of the Alstr?m syndrome 1(ALMS1)gene.We report a case of AS,extend the spectrum of ALMS1 mutations and highlight the biological role of ALMS1 to explore the relationship between dilated cardiomyopathy(DCM)and mutations in ALMS1.CASE SUMMARY We present the case of an infant with AS mainly manifesting with DCM that was caused by a novel mutation of the ALMS1 gene.Whole-exome sequencing revealed a simultaneous large deletion and point mutation in ALMS1,leading to frameshift and missense mutations,respectively,rather than nonsense or frameshift mutations,which have been reported previously.Upon optimized anti-remodeling therapy,biohumoral exams and arrhythmic burden of the infant were alleviated at follow-up after 6 mo.CONCLUSION We identified novel mutations of ALMS1 and extended the spectrum of ALMS1 mutations in an infant with AS.

Novel MIP gene mutation causes autosomal-dominant congenital cataract

●AIM:To identify disease-causative mutations in families with congenital cataract.●METHODS:Two Chinese families with autosomaldominant congenital cataract(ADCC)were recruited and underwent comprehensive eye examinations.Gene panel next-generation sequencing of common pathogenic genes of congenital cataract was performed in the proband of each family.Sanger sequencing was used to valid the candidate gene mutations and sequence the other family members for co-segregation analysis.The effect of sequence changes on protein structure and function was predicted through bioinformatics analysis.Major intrinsic protein(MIP)-wildtype and MIP-G29R plasmids were constructed and microinjected into zebrafish single-cell stage embryos.Zebrafish embryonic lens phenotypes were screened using confocal microscopy.●RESULTS:A novel heterozygous mutation(c.85G>A;p.G29R)in the MIP gene was identified in the proband of one family.A known heterozygous mutation(c.97C>T;p.R33C;rs864309693)in MIP was found in the proband of another family.In-silico prediction indicated that the novel mutation might affect the MIP protein function.Zebrafish embryonic lens was uniformly transparent in both wild-type PCS2+MIP and mutant PCS2+MIP.●CONCLUSION:Two missense mutations in the MIP gene in Chinese cataract families are identified,and one of which is novel.These findings expand the genetic spectrum of MIP mutations associated with cataracts.The functional studies suggest that the novel MIP mutation might not be a gain-of-function but a loss-of-function mutation.

Circulating tumor DNA genomic profiling reveals the complicated olaparib-resistance mechanism in prostate cancer salvage therapy: A case report

BACKGROUND The poly(ADP-ribose)polymerase(PARP)inhibitor olaparib has displayed superior clinical effect in metastatic castration-resistant prostate cancer(mCRPC)patients with the homologous recombination repair(HRR)genes mutations.However,when a patient’s tumor tissue volume is insufficient for genomic profiling of HRR gene mutations,circulating tumor DNA(ctDNA)may be useful in helping to determine and monitor the efficacy of olaparib,as well as in abiraterone-combination treatment,and for understanding any resistance mechanism related to such mutations.CASE SUMMARY A 61-year-old man who was diagnosed with metastatic prostate adenocarcinoma was initially hormone sensitivity,showing high Gleason score(5+5=10)and absolute positive rate(14/14 biopsied specimens).Following failure of several standard therapies,the patient progressed to mCRPC.Surprisingly,the patient showed good response to olaparib-abiraterone-prednisone combination treatment(an androgen-deprivation therapy,provided as the‘final choice’in China).Serum total prostate-specific antigen(TPSA)level reduced and symptoms remitted for 4 months.However,thereafter,serum TPSA levels began slowly increasing,indicating development of olaparib resistance.Subsequent comprehensive genomic profiling of ctDNA, screening 508 cancer-related genes by next-generation sequencing,identified 10 somatic variants as well as 3 copy number alterations. Two identified reversemissense mutations in partner and localizer of BRCA2 (PALB2) may have recovered the readingframe, restoring function of the primary germline PALB2 mutation and causing resistance to thePARP inhibitor olaparib.CONCLUSIONReverse mutations in PALB2, discovered via genomic profiling of ctDNA, may represent apotential resistance mechanism against olaparib in mCRPC.

A novel mutation of LIM2 causes autosomal dominant membranous cataract in a Chinese family

AIM:To identify mutations in the genes of a fourgeneration Chinese family with congenital membranous cataracts and investigate the morphologic changes and possible functional damage underlying the role of the mutant gene.METHODS:Whole exome analysis of thirteen members of a four-generation pedigree affected with congenital membranous cataracts was performed;co-segregation analysis of identified variants was validated by Sanger sequencing.All members underwent detailed physical and complete eye examinations.The physical changes caused by the mutation were analyzed in silico through homology modeling.The lens fiber block from a patient was observed under a scanning electron microscope(SEM).Cell membrane proteins and cytoplasmic proteins from the human lenses donated by one patient with cataract in this family and from the dislocated lens resulted from the penetrating ocular trauma of a patient unrelated with this family were extracted,and the expression and localization of MP20 and Cx46 were detected by Western blot(WB)assay in these proteins.RESULTS:A novel LIM2 heterozygous mutation(c.388 C>T,p.R130 C)was identified with congenital membranous cataracts inherited by an autosomal dominant(AD)pattern.Nystagmus and amblyopia were observed in all patients of this family,and exotropia and long axial length were observed in most patients.A/B ultrasound scan and ultrasound biomicroscopy revealed obvious thin crystalline lenses from 1.7 to 2.7 mm in central thickness in all cataract eyes.The bioinformatic analysis showed that the mutation was deleterious to the physiological function of LIM2-encoded MP20.Furthermore,by SEM,ultrastructure of the cataract nucleus showed that lens fiber cells(LFCs)remained morphologic characteristics of immature fiber cells,including flap cell surface with straight edges and lacking normal ball-and-socket joint boundaries,which implied that the differentiation of LFCs might be inhibited.Accumulation of MP20 and Cx46 in the cytoplasm was observed in the cytoplasm of the LFCs in human cataract lens.CONCLUSION:We identify a novel heterozygous LIM2(c.388 C>T,p.R130 C)mutation inherited by an AD pattern.This LIM2 mutation causes the abnormal sub-localization of MP20 and Cx46 in LFCs resulting in membranous cataracts.

In silico analysis of a disease-causing mutation in PCDH15 gene in a consanguineous Pakistani family with Usher phenotype

AIM： To map Usher phenotype in a consanguineous Pakistani family and identify disease-associated mutation in a causative gene to establish phenotype-genotype correlation.· METHODS： A consanguineous Pakistani family in which Usher phenotype was segregating as an autosomal recessive trait was ascertained. On the basis of results of clinical investigations of affected members of this family disease was diagnosed as Usher syndrome（USH）. To identify the locus responsible for the Usher phenotype in this family, genomic DNA from blood sample of each individual was genotyped using microsatellite Short Tandem Repeat（STR） markers for the known Usher syndrome loci. Then direct sequencing was performed to find out disease associated mutations in the candidate gene.· RESULTS： By genetic linkage analysis, the USH phenotype of this family was mapped to PCDH15 locus on chromosome 10q21.1. Three different point mutations in exon 11 of PCDH15 were identified and one of them,c.1304AC was found to be segregating with the disease phenotype in Pakistani family with Usher phenotype.This, c.1304 A C transversion mutation predicts an amino-acid substitution of aspartic acid with an alanine at residue number 435（p.D435A） of its protein product.Moreover, in silico analysis revealed conservation of aspartic acid at position 435 and predicated this change as pathogenic.·CONCLUSION：Theidentificationofc.1304ACpathogenic mutation in PCDH15 gene and its association with Usher syndrome in a consanguineous Pakistani family is thefirst example of a missense mutation of PCDH15 causing USH1 phenotype. In previous reports, it was hypothesized that severe mutations such as truncated protein of PCDH15 led to the Usher I phenotype and that missense variants are mainly responsible for non-syndromic hearing impairment.

Newly Found C1 Inhibitor Gene Mutation in Hereditary Angioedema Patients

Hereditary angioedema （HAE） is an autosomal dominant condition that affects one in about 50 000 persons, characterized by recurrent episodes of subcutaneous or submucosal swelling involving the hands, feet, limbs, face, intestinal tract, even larynx and trachea.

A novel missense mutation of CCDC34 causes male infertility with oligoasthenoteratozoospermia in a consanguineous Pakistani family

Male infertility is a worldwide health issue,affecting 8%–12%of the global population.Oligoasthenoteratozoospermia(OAT)represents a severe type of male infertility,characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology.Using whole-exome sequencing,this study identified a novel missense mutation(c.848C>A,p.A283E)in the coiled-coil domain-containing 34 gene(CCDC34)in a consanguineous Pakistani family.This rare mutation was predicted to be deleterious and to affect the protein stability.Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms.These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms,thus expanding the phenotypic spectrum of CCDC34 missense mutations.

A Novel Missense Mutation in Peripheral Myelin Protein-22 Causes Charcot-Marie-Tooth Disease

Background：Charcot-Marie-Tooth disease （CMT） is the most common inherited peripheral neuropathy.A great number of causative genes have been described in CMT,and among them,the heterozygous duplication of peripheral myelin protein-22 （PMP22） is the major cause.Although the missense mutation in PMP22 is rarely reported,it has been demonstrated to be associated with CMT.This study described a novel missense mutation of PMP22 in a Chinese family with CMT phenotype.Methods：Targeted next-generation sequencing （NGS） was used to screen the causative genes in a family featured with an autosomal dominant demyelinating form of CMT.The potential variants identified by targeted NGS were verified by Sanger sequencing and classified according to the American College of Medical Genetics and Genomics standards and guidelines.Further cell transfection studies were performed to characterize the function of the novel variant.Results：Using targeted NGS,a novel heterozygous missense variant in PMP22 （c.320G〉A,p.G107D） was identified.In vitro cell functional studies revealed that mutant PMP22 protein carrying p.G 107D mutation lost the ability to reach the plasma membrane,was mainly retained in the endoplasmic reticulum,and induced cell apoptosis.Conclusions：This study supported the notion that missense mutations in PMP22 give rise to a CMT phenotype,possibly through a toxic gain-of-function mechanism.

A Novel Functional Missense Mutation p.T219A in Type Gaucher＇s Disease

Background： Gaucher＇s disease （GD） is an autosomal recessive disorder caused by a deficiency of acid β-glucosidase （glucocerebrosidase [GBA]） that results in the accumulation of glucocerebroside within macrophages. Many mutations have been reported to be associated with this disorder. This study aimed to discover more mutations and provide data for the genetic pattern of the gene, which will help the development of quick and accurate genetic diagnostic tools for this disease. Methods： Genomic DNA was obtained from peripheral blood leukocytes of the patient and Sanger sequencing is used to sequence GBA gene. Sequence alignments of mammalian β-GBA （GCase） and three-dimensional protein structure prediction of the mutation were made. A construct of this mutant and its compound heterozygous counterpart were used to measure GCase in vitro. Results： GCase is relatively conserved at p.T219A. This novel mutation differs from its wild-type in structure. Moreover, it also causes a reduction in GCase enzyme activity. Conclusion： This novel mutation （c.655A〉G, p.T219A） is a pathogenic missense mutation, which contributes to GD.