A questionnaire study for 128 patients with Gaucher disease

Gaucher disease is an uncommon autosomal recessive disorder characterized by lysosomal storage of glucosyl ceramide, a material released during cell degradation. Patients with Gaucher disease often have significant hematologic, bone structural, and visceral problems which sometimes greatly affect their health and life style. Based on some extraordinary scientific discoveries over the past 45 years, a treatment system has evolved which consists of administration of an enzyme, which destroys the lysosome-stored material and to some extent restores the patients to good health. There are still some problems for these patients; however, and the purpose of the study is to define some of the clinical, sociologic, and psychologic problems with a specially designed questionnaire. Questionnaire data was collected for 128 patients from two institutions with complete anonymity, and the information compared against data from a National Health Interview Survey. The results show that many of the patients still have fairly extensive problems, which could possibly be helped by some alterations in treatment protocols.

A Chaperone-Mediated Approach to??Enzyme Enhancement as a Therapeutic Option for the Lysosomal??Storage Disorders

Enzyme activity can be deficient in the lysosome because certain newly synthesised mutation-bearing proteins are unstable and prone to misfolding. These structurally defective proteins are detected by the quality control system in the endoplasmic reticulum and subsequently diverted to cellular pathways of degradation. Recent studies have shown that low molecular weight ligands that are competitive inhibitors for some of these lysosomal enzymes can, in subinhibitory concentrations, act as 'chaperones' and rescue the mutant proteins, leading to the reconstitution of their hydrolytic activity within the lysosome. The potential of these agents as a therapeutic option will be dependent on their safety and tolerability profile, and the absence of toxic metabolic byproducts resulting from their use; there should be no or minimal nonspecific interference with other physiological or adaptive cellular activities. Compared with enzyme replacement therapy, the plausible advantages of using small molecule chaperones derive from the ease of oral administration, lack of immunogenicity and the possibility of delivery across the blood-brain barrier; and thus the potential to treat neurodegenerative clinical variants. The major challenges in developing therapies for rare diseases, such as the lysosomal storage disorders (LSDs), include recruitment of a sufficient number of suitable study patients and establishment of the optimal (dose/frequency) regimen to achieve a meaningful outcome. Multiple therapeutic approaches for the LSDs will provide patients with a range of options, which may be adequate as singular strategies or when given in combination. This review examines the characteristics of select agents that represent current candidates for a chaperone-mediated approach to the treatment of a subgroup of the LSDs, specifically the glycosphingolipidoses. Clinical trial experience with the use of these drugs will clarify their position in the management algorithm, which currently has enzyme replacement therapy as its linchpin. A major therapeutic goal would be improved physical and functional wellbeing, leading to increased meaningful survival.

MR imaging and proton spectroscopy of neuronal injury in late-onset GM2 gangliosidosis

BACKGROUND AND PURPOSE

Despite the ubiquity of G(M2) gangliosides accumulation in patients with late-onset G(M2) gangliosidosis (G(M2)G), the only clinical MR imaging-apparent brain abnormality is profound cerebellar atrophy. The goal of this study was to detect the presence and assess the extent of neuroaxonal injury in the normal-appearing gray and white matter (NAGM and NAWM) of these patients.

METHODS

During a single imaging session, 9 patients with late-onset G(M2)G and 8 age-matched normal volunteers underwent the following protocol: (1) T1- and T2-weighted and fluid-attenuated inversion recovery MR images, as well as (2) multivoxel proton MR spectroscopy (1H-MR spectroscopy) to quantify the distribution of the n-acetylaspartate (NAA), creatine (Cr), and choline (Cho), were obtained.

RESULTS

The patients' NAA levels in the thalamus (6.5 +/- 1.9 mmol/L) and NAWM (5.8 +/- 2.1 mmol/L) were approximately 40% lower than the controls' (P = .003 and P = .005), whereas the Cr and Cho reductions ( approximately 30% and approximately 26%) did not reach significance (P values of .06-.1). All cerebellar metabolites, especially NAA and Cr, were much (30%-90%) lower in the patients, which reflects the atrophy.

CONCLUSION

In late-onset G(M2)G, NAA decreases are detectable in NAGM and NAWM even absent morphologic (MR imaging) abnormalities. Because the accumulation of G(M2) gangliosides can be reduced pharmacologically, 1H-MR spectroscopy might be a sensitive and specific for detecting and quantifying neuroaxonal injury and monitoring response to emerging treatments.

Individualization of long-term enzyme replacement therapy for Gaucher disease

Gaucher disease, the most common lysosomal storage disorder, is a heterogeneous condition affecting multiple organ systems. Patients with nonneuronopathic (type 1) Gaucher disease may suffer from hepatomegaly, splenomegaly, thrombocytopenia, bleeding tendencies, anemia, hypermetabolism, skeletal pathology, growth retardation, pulmonary disease, and decreased quality of life. Enzyme replacement therapy (ERT) with mannose-terminated glucocerebrosidase (imiglucerase, Cerezyme, Genzyme Corporation, Cambridge, MA) reverses or ameliorates many of the manifestations of type 1 Gaucher disease. However, due to the variable pattern and severity of disease, and the uncertain manner of progression, implementation of treatment, choice of initial and maintenance imiglucerase dose, and evaluation of the therapeutic response must be tailored to the individual patient. For the past 14 years, the US Regional Coordinators of the International Collaborative Gaucher Group have individually and collectively developed extensive clinical experience in managing patients with Gaucher disease. In this review, we present recommendations for initial imiglucerase treatment and subsequent dose adjustments based on a schedule of regular assessment and monitoring, and achievement and maintenance of defined therapeutic goals.

Late-onset Tay-Sachs disease: phenotypic characterization and genotypic correlations in 21 affected patients

PURPOSE

The purpose of this study was to describe the phenotype (and corresponding genotype) of adult patients with late-onset Tay-Sachs disease, a clinical variant of the GM2-gangliosidoses.

METHODS

A comprehensive physical examination, including neurological assessments, was performed to establish the current disease pattern and severity. In addition, the patients' past medical histories were reviewed. The patients' alpha-subunit mutations (beta-Hexosaminidase A genotype) were determined and correlated with their corresponding clinical findings and disease course.

RESULTS

Twenty-one patients (current mean age: 27.0 years; range: 14-47 years) were identified. The pedigree revealed a relative with the "classic" infantile or late-onset form of Tay-Sachs disease in four (out of 18) unrelated families. The patients were predominantly male (15/21 individuals) and of Ashkenazi Jewish ancestry (15/18 families). Mean age at onset was 18.1 years; balance problems and difficulty climbing stairs were the most frequent presenting complaints. In several cases, the diagnosis was delayed (mean age at diagnosis: 27.0 years). Analysis of the beta-hex A gene revealed the G269S mutation as the most common disease allele; found in homozygosity (N = 1) or heterozygosity (N = 18; including 2 sib pairs). Disease onset (age 36 years) was delayed and progression relatively slower in the homozygous G269S patient. Two siblings (ages 28 and 31 years), of non-Jewish ancestry, were compound heterozygotes (TATC1278/W474C); their clinical course is dominated by psychiatric problems. Brain imaging studies revealed marked cerebellar atrophy in all patients (N = 18) tested, regardless of disease stage.

CONCLUSIONS

Late-onset Tay-Sachs disease is an infrequent disorder and the diagnosis is often missed or delayed (by approximately 8 years). Early on, the majority of patients develop signs of either cerebellar or anterior motor neuron involvement. Affected individuals may also develop psychotic episodes. In most cases, the later-onset of expression results from the presence of at least one allele (usually the G269S mutation), associated with residual enzyme (beta-hexosaminidase A) activity. A positive family history is a valuable clue, enabling early diagnosis. Nonspecific cerebellar atrophy on brain imaging is another important finding. This entity should be considered among patients presenting with speech, gait, and balance problems, and those with psychiatric disorders even when focal neurologic deficits may be initially absent. Accurate diagnosis will permit appropriate genetic counseling regarding disease prognosis and reproductive risks.

Therapeutic goals in the treatment of Gaucher disease

Gaucher disease, the most common lysosomal storage disorder, is a heterogeneous multisystem condition. Patients with non-neuronopathic (type 1) Gaucher disease may suffer from hepatomegaly, splenomegaly, thrombocytopenia, bleeding tendencies, anemia, hypermetabolism, skeletal pathology, growth retardation, pulmonary disease, and decreased quality of life. Enzyme replacement therapy (ERT) with mannose-terminated glucocerebrosidase reverses or ameliorates many of the manifestations of type 1 Gaucher disease. However, the variable disease pattern and severity, and the uncertain manner of progression, render the decision to initiate ERT difficult. Thus, implementation of treatment and evaluation of the therapeutic response must be tailored to the individual patient. To obtain an evidence-based consensus on contemporary therapeutic goals, an international panel of physicians with extensive clinical experience in Gaucher disease met to review the extant literature on its treatment. The panel adopted an integrated system-based approach to arrive at a comprehensive guide to individualized management. Here we establish goals of treatment in Gaucher disease and propose a comprehensive schedule of monitoring of all relevant aspects to confirm the achievement, maintenance, and continuity of the therapeutic response.

Musculoskeletal complications associated with lysosomal storage disorders: Gaucher disease and Hurler-Scheie syndrome (mucopolysaccharidosis type I)

PURPOSE OF REVIEW

Enzyme therapy for lysosomal storage disorders directed at correcting the underlying cause of disease represents the most significant recent advance in patient management. This review focuses on two disease groups: glycosphingolipidoses and mucopolysaccharidoses. Specifically, Gaucher disease and Hurler-Scheie syndrome have been selected as the prototypical disorder for each respective class.

RECENT FINDINGS

Musculoskeletal complications are encountered in several of the lysosomal storage disorders and often represent a major source of extraneurologic morbidity, particularly in the subacute or chronic variants. Enzyme therapy has led to improvements in physical and functional well-being. However, bone involvement remains a recalcitrant feature, especially among patients with established disease before institution of therapy.

SUMMARY

Early diagnosis and appropriate timely intervention are critical in achieving the best therapeutic results. A better understanding of the fundamental mechanisms of bone pathology may enable the identification of complementary approaches (eg, the use of bisphosphonates for severe osteopenia) for optimized outcomes. Symptomatic care and rigorous physical and occupational therapy remain critical components of a comprehensive management approach.

Thirty-four novel mutations of the GLA gene in 121 patients with Fabry disease

Fabry disease (FD) is an X-chromosomal disorder caused by mutations in the GLA gene encoding the lysosomal enzyme alpha-galactosidase A. We performed mutation screening on a cohort of 121 patients including 84 male and 37 female index cases and identified a total of 90 different mutations, 34 of which are reported for the first time here. Both point mutations (74.4%) and 'short length' rearrangements (25.6%) were found, including missense (54.4%), nonsense (14.4%), and splice site point mutations (5.6%), deletions (17.8%) or insertions/duplications (5.6%) of a few nucleotides, and complex rearrangements including larger deletions (2.2%). GLA mutations were identified in 82 (97.6%) of the 84 unrelated male patients.

Globoid cell leukodystrophy (Krabbe disease): normal umbilical cord blood galactocerebrosidase activity and polymorphic mutations

Globoid cell leukodystrophy is an inherited metabolic disorder of the central nervous system caused by deficiency of the lysosomal enzyme galactocerebrosidase. Haematopoietic stem cell transplantation is the only available effective treatment. The engraftment from normal donors provides competent cells able to correct the metabolic defect. Umbilical cord blood cells have proved to significantly decrease complications and improve engraftment rate compared to adult marrow cells in haematopoietic stem cell transplantation. Umbilical cord blood cells must be of sufficient activity to provide central nervous system recovery after engraftment is obtained. Galactocerebrosidase activity is known to be affected by two polymorphic alleles found at nucleotides 502 and 1637 of the cDNA for this gene. This enzyme activity and the polymorphic alleles noted above were analysed in 83 random samples of umbilical cord blood. The activity, assayed with the fluorogenic substrate 6-hexadecanoylamino-4-methylumbelliferyl-beta-galactopyranoside, in those with neither polymorphic allele was 4.6 +/- 1.7 units (nmol/h per mg protein). This optimal choice of cord blood was found in only 24% of specimens. Homozygotes for 1637T > C with activity of only 1.5 +/- 0.4 units represented 16% of the samples. Those heterozygous for 1637T > C with slightly better activity (2.3 +/- 0.7 units) represented 52% of the samples. Choice of umbilical cord blood for haematopoietic stem cell transplantation, therefore, requires consideration not only of cell quantity and HLA compatibility but also selection for normal alleles to obtain maximal enzymatic activity for central nervous system correction.

Neuropsychological assessment of patients with late onset GM2 gangliosidosis

OBJECTIVE

To characterize cognitive status in a sample of individuals with late-onset GM2 gangliosidosis (commonly referred to as late-onset Tay-Sachs disease).

METHODS

Seventeen subjects (13 men, 4 women) diagnosed with GM2 gangliosidosis were evaluated. Subjects ranged in age from 18 to 56 years and were in various stages of disease progression. Subjects underwent comprehensive neuropsychological assessment. Impairment was defined as performance more than 1.6 SD below the normative mean.

RESULTS

Group mean performance was within the denoted normal range on all measures except on a task assessing visual sequencing and set shifting. Approximately one-half of the sample scored in the impaired range on measures of processing speed, visual sequencing, and set shifting. One-third of the sample also scored in the impaired range on measures of delayed verbal recall. Impairment tended to be restricted to a subset of the sample, as 5 of the 14 subjects able to undergo formal testing accounted for 70% of the total number of impaired scores. If the three subjects unable to participate in formal testing are also considered impaired, 47% of the current sample exhibited significant cognitive impairment in at least one cognitive domain.

CONCLUSION

In late-onset GM2 gangliosidosis, there is a risk of impairment in executive functioning and memory as well as cerebellar dysfunction. Dementia was not present in any subjects in the current sample.

Gaucher disease type 1: Revised recommendations on evaluations and monitoring for adult patients

For patients with type 1 Gaucher disease, challenges to patient care posed by clinical heterogeneity, variable progression rates, and potential permanent disability that can result from untreated or suboptimally treated hematologic, skeletal, and visceral organ involvement dictate a need for comprehensive, serial monitoring. An updated consensus on minimum recommendations for effective monitoring of all adult patients with type 1 Gaucher disease has been developed by the International Collaborative Gaucher Group (ICGG) Registry coordinators. These recommendations provide a schedule for comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects of this disease. The initial assessment should include confirmation of deficiency of beta-glucocerebrosidase, genotyping, and a complete family medical history. Other assessments to be performed initially and at regular intervals include a complete physical examination, patient-reported quality of life using the SF-36 survey, and assessment of hematologic (hemoglobin and platelet count), visceral, and skeletal involvement, and biomarkers. Specific radiologic imaging techniques are recommended for evaluating visceral and skeletal pathology. All patients should undergo comprehensive regular assessment, the frequency of which depends on treatment status and whether therapeutic goals have been achieved. Additionally, reassessment should be performed whenever enzyme therapy dose is altered, or in case of significant clinical complication.

Enzyme replacement therapy for mucopolysaccharidosis I: a randomized, double-blinded, placebo-controlled, multinational study of recombinant human alpha-L-iduronidase (laronidase)

OBJECTIVE

To confirm the efficacy and safety of recombinant human alpha-L-iduronidase (laronidase) in patients with mucopolysaccharidosis I (MPS I).

STUDY DESIGN

This was a randomized, double-blinded, multinational study of 45 patients with MPS I administered 100 U/kg (0.58 mg/kg) laronidase, or placebo intravenously weekly for 26 weeks. The coprimary efficacy end points compared the median change from baseline to week 26 between groups in percentage of predicted normal forced vital capacity (FVC) and in 6-minute walk test (6MWT) distance through the use of the Wilcoxon rank sum test.

RESULTS

The laronidase (n=22) and placebo (n=23) groups had similar baseline characteristics. After 26 weeks, patients receiving laronidase compared with placebo showed mean improvements of 5.6 percentage points in percent of predicted normal FVC (median, 3.0; P=.009) and 38.1 meters in 6MWT distance (median, 38.5; P=.066; P=.039, analysis of covariance). Laronidase also significantly reduced hepatomegaly and urinary glycosaminoglycans, and, in more severely affected patients, improved sleep apnea/hypopnea and shoulder flexion. Laronidase was well-tolerated. Nearly all patients receiving enzyme had development of IgG antibodies, without apparent clinical effects.

CONCLUSIONS

In patients with MPS I, laronidase significantly improves respiratory function and physical capacity, reduces glycosaminoglycan storage, and has a favorable safety profile.

Pulmonary involvement in type 1 Gaucher disease: functional and exercise findings in patients with and without clinical interstitial lung disease

Pulmonary disease is a well-known complication of Type 1 Gaucher disease (GD), although its incidence is not well established and its severity varies. The purpose of this study was to determine the frequency and extent of pulmonary involvement in patients with GD. Pulmonary involvement was assessed by history, physical examination and chest radiograph in 150 consecutive patients with Type 1 GD presenting at a specialized center for genetic diseases. Five patients were noted to have clinical evidence of pulmonary involvement. Full pulmonary function tests were performed in these five patients and in an additional 13 patients randomly selected from the remaining 145. Many of the 18 patients also underwent radionuclide body imaging with 67 Gallium citrate and 111Indium-tagged leucocyte scans, as well as incremental cardiorespiratory exercise tests. Lung biopsies were available in two patients with lung disease, and a second examination of lung tissue was performed in one of these two patients post-mortem. Clinical lung disease was detected in five patients. All five had dyspnea, diffuse infiltrates, restrictive impairment and low single breath CO diffusing capacity (DLCOSB). Two of these patients underwent exercise testing and showed abnormalities consistent with lung disease (ventilatory limitation, excessive ventilation and increased dead space) as well as decreased VO2 max. and anaerobic threshold (AT). In contrast, in the other 13 patients, physical examination, chest radiographs and pulmonary function were normal (except for a low DLCOSB in one patient). Responses on exercise testing (performed in six of the 13 patients) were consistent with a circulatory impairment (decreased VO2 max. and AT). Our study found that <5% of patients with Type 1 GD have clinical interstitial lung disease. In addition, we found that some patients, without evident lung involvement, may experience limitations in physical exertion and are easily fatigued; this is attributable to impaired circulation.

Extended interval between enzyme therapy infusions for adult patients with Gaucher's disease type 1

BACKGROUND

Enzyme replacement therapy (ERT) for Gaucher's disease with alglucerase or imiglucerase is efficacious, well-tolerated and safe. However, cost considerations, visits to medical facilities, potentially duration of theray for life, are issues of major concern to a proportion of treated patients and has, in some cases, led to the withdrawal of therapy.

AIMS

To elucidate whether an extension of the interval between enzyme infusions to once every three weeks is as effective in maintaining the clinical responses achieved with the bi-monthly regimen.

MATERIALS AND METHODS

Four patients with an optimal response to ERT (at 30 units/kg every two weeks for an average of 27 months), were subjected to enzyme dose/frequency changes that essentially constituted a reduction in cumulative dose over the treatment period. Patients were assessed every 6 months for alterations in haematological parameters, plasma chitotriosidase levels, liver and spleen size, and bone symptoms.

RESULTS

All patients had to resume the previous infusion schedule of once every two weeks; one because of new bone marrow infiltrates, two because of visceral enlargement, and the fourth due to progressive anaemia.

CONCLUSIONS

This limited experience suggests that a reduction in enzyme dose associated with an extended interval between infusions may lead to variable disease control, and underscores the need for individualization of enzyme therapy.

Substrate reduction therapy: miglustat as a remedy for symptomatic patients with Gaucher disease type 1

Gaucher disease (GD) is an inborn error of glycosphingolipid metabolism, associated with multisystemic manifestations resulting from the lysosomal accumulation of an incompletely degraded material (glucosylceramide) within cells of monocyte/macrophage lineage. In the majority of GD patients with non-neurological involvement (type 1), the clinical features are dominated by haematological, visceral (hepatic and splenic) and skeletal complications. Infrequently, cardiopulmonary involvement may develop and lead to major morbidity. Investigations of substrate turnover within cellular compartments, such as the lysosome, indicate that progressive tissue storage occurs when the activity of the responsible hydrolytic enzyme declines. Thus, the provision of functional enzyme to deficient cells is a straightforward means of achieving metabolic correction. Conversely, the concentration of stored substrate within cells bearing particular affected enzymes (i.e., expressing residual activity) may be controlled by a reduction of the 'load'. This means that metabolic homeostasis can also be restored by restricting the amount of substrate presented to disease cells to a level that can be hydrolysed by the existing enzyme activity. Proof-of-concept for both approaches has been demonstrated through enzyme replacement therapy using alglucerase/imiglucerase and more recently, substrate reduction therapy by miglustat. Enzyme replacement therapy is proven to be safe and effective in the treatment of GD type 1, establishing imiglucerase as the current standard of care. The experience with substrate reduction therapy, specifically miglustat, is limited but encouraging. This review is an attempt to examine the potential role of this latter approach in light of current patient management. The consideration of miglustat as a therapeutic option requires the appropriate selection of patients (amongst those unwilling or unsuitable to receive enzyme replacement therapy), a definition of the therapeutic objectives and monitoring not only for response but potential adverse effects.

The role of the iminosugar N-butyldeoxynojirimycin (miglustat) in the management of type I (non-neuronopathic) Gaucher disease: a position statement

N-Butyldeoxynojirimycin (NB-DNJ, miglustat 'Zavesca') is an orally active iminosugar which inhibits the biosynthesis of macromolecular substrates that accumulate pathologically in glycosphingolipidoses. Clinical trials of NB-DNJ in patients with Gaucher's disease demonstrate the therapeutic potential of such substrate inhibitors in the glycolipid storage disorders. However, macrophage-targetted enzyme replacement using intravenous mannose-terminated human glucocerebrosidase (imiglucerase, Cerezyme) is highly effective in ameliorating many of the manifestations of Gaucher's disease and is a treatment in widespread use. Given that imiglucerase and miglustat are now both licensed for the treatment of Gaucher's disease, there is a need to review their therapeutic status. Here the treatment of type 1 (non-neuronopathic) Gaucher disease is evaluated with particular reference to the emerging role of oral N-butyldeoxynojirimycin (miglustat) as a substrate-reducing agent. This position statement represents the consensus viewpoint of an independent international advisory council to the European Working Group on Gaucher Disease.

A neurological symptom survey of patients with type I Gaucher disease

Gaucher disease is an inborn error of glycosphingolipid metabolism resulting from deficiency of the lysosomal enzyme glucocerebrosidase. The majority of the patients (with type I disease) do not have primary central nervous system involvement. However, several studies have noted that secondary neurological complications may develop as a consequence of nerve root or spinal cord compression following vertebral body collapse or, for those with coagulation disorders, bleeding within confined compartments. An epidemiological survey was conducted to ascertain the incidence of neurological symptoms in patients with Gaucher disease type I (GD I). The survey included a review of the patients' medical history, an estimate of Gaucher disease severity according to a modified Symptom Severity Index (SSI), and completion of a questionnaire regarding their neurological status and Quality of Life (QoL) according to the SF-36 Health Survey. Seventy-three per cent of respondents were found to have experienced at least one neurological complaint in the preceding 3 months. Adult patients with Gaucher disease often have other medical problems unrelated to their primary diagnosis. Thus, the high incidence of neurological complaints in these patients may be attributable to concurrent medical problems and/or side-effects from concomitant medications. These issues may influence patients' assessment of their disease severity and/or response to treatment.

Therapeutic effects of astrocytes expressing both tyrosine hydroxylase and brain-derived neurotrophic factor on a rat model of Parkinson's disease

Tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF), expressed in normal astrocytes, were used in combination for the treatment of Parkinson's disease (PD) symptoms in a rat model. Normal neonatal rat astrocytes were co-transfected with a vector expressing BDNF (AAVBDNF) and a retroviral vector expressing TH (termed TH-BDNF-DA(+) cells), and then implanted into the striatum of PD rats induced by 6-hydroxydopamine. TH-BDNF-DA(+) cells compensated for a severe insufficiency of endogenous dopaminergic neurons in the PD rats, resulting in a significant improvement of PD symptoms. The decrease in the rotational rate of PD rats implanted with TH-BDNF-DA(+) cells was more marked than that in PD rats implanted with normal astrocytes expressing either TH or BDNF alone (termed TH(+) and BDNF(+) cells, P<0.01 and 0.001, respectively), and suggested a synergistic effect between TH and BDNF. In contrast, the rotational rate was not altered from the baseline in PD rats without treatment or implanted with parental rat astrocytes alone (P>0.05). BDNF protected the dopaminergic neurons from apoptosis induced by 6-hydroxydopamine, and significantly increased the long-term survival of TH-positive cells in the striatum. Our data indicate that the combined use of TH and BDNF has a synergistic therapeutic effect, and is more efficient for the treatment of PD than a single gene therapy using either TH or BDNF alone.

Identification and characterization of novel mutations of the aspartoacylase gene in non-Jewish patients with Canavan disease

Canavan disease, an inherited leukodystrophy, is caused by mutations in the aspartoacylase (ASPA) gene. It is most common among children of Ashkenazi Jewish descent but has been diagnosed in many diverse ethnic groups. Two mutations comprise the majority of mutant alleles in Jewish patients, while mutations in the ASPA gene among non-Jewish patients are different and more diverse. In the present study, the ASPA gene was analysed in 22 unrelated non-Jewish patients with Canavan disease, and 24 different mutations were found. Of these, 14 are novel, including five missense mutations (E24G, D68A, D249V, C152W, H244R), two nonsense mutations (Q184X, E214X), three deletions (923delT, 33del13, 244delA), one insertion mutation (698insC), two sequence variations in one allele ([10T>G; 11insG]), an elimination of the stop codon (941A>G, TAG-->TGG, X314W), and one splice acceptor site mutation (IVS1 - 2A>T). The E24G mutation resulted in substitution of an invariable amino acid residue (Glu) in the first esterase catalytic domain consensus sequence. The IVS1 - 2A>T mutation caused the retention of 40 nucleotides of intron 1 upstream of exon 2. The results of transient expression of the mutant ASPA cDNA containing these mutations in COS-7 cells and assays for ASPA activity of patient fibroblasts indicated that these mutations were responsible for the enzyme deficiency. In addition, patients with the novel D249V mutation manifested clinically at birth and died early. Also, patients with certain other novel mutations, including C152W, E214X, X314W, and frame shift mutations in both alleles, developed clinical manifestations at an earlier age than in classical Canavan disease.

High prevalence of the 55-bp deletion (c.1263del55) in exon 9 of the glucocerebrosidase gene causing misdiagnosis (for homozygous N370S (c.1226A > G) mutation) in Spanish Gaucher disease patients

Gaucher disease (GD) is the most frequent lysosomal storage disease, caused by mutations in the acid beta-glucosidase gene (GBA). The c.1226A > G (N370S) mutation is associated with non-neuronopathic disease (type 1). However, we have observed some discrepancy between genotype and phenotype in Spanish Gaucher disease patients homozygous for the c.1226A > G mutation. A deletion of 55 bp in the exon 9 GBA gene, corresponding to the deleted portion of the beta-glucosidase pseudogene, has been previously reported as a cause of erroneous assignment of 1226G/1226G homozygous patients when the genotype has been performed by PCR assay. We had originally identified 25 (out of 124) unrelated Gaucher disease patients as being putative homozygotes for the c.1226A > G mutation. By means of a new PCR-based assay, we were able to distinguish between the true homozygous patients and the carriers of the 55-bp deletion in exon 9 of the GBA gene. The 55-bp deletion was detected in 10 out of 25 samples (40%) [7 with the 55-bp deletion, 1 RecTL, 1 RecNciI (both including the deletion) and one rearrangement]. Such a high prevalence in this sample suggests that this allele can be more common than expected among GD patients.