Occurrence of Amyotrophic Lateral Sclerosis in Type 1 Gaucher Disease.

OBJECTIVE: To report the association between type 1 Gaucher disease (GD1) and amyotrophic lateral sclerosis (ALS) in 3 unrelated families and to explore whether GBA variants influence the risk of ALS. METHODS: We conducted retrospective chart reviews of patients with GD1 or their family members diagnosed with ALS. To further investigate whether there is an association between ALS and GD, we performed exploratory analyses for the presence of GBA variants in 3 ALS cohorts from Toronto (Canada), Montreal (Canada), and Project MinE (international), totaling 4,653 patients with ALS and 1,832 controls. RESULTS: We describe 2 patients with GD1 and 1 obligate GBA mutation carrier (mother of GD1 patient) with ALS. We identified 0 and 8 GBA carriers in the Toronto and Montreal cohorts, respectively. The frequencies of GBA variants in patients with ALS in the Montreal and Project MinE cohorts were similar to those of Project MinE controls or Genome Aggregation Database population controls. CONCLUSIONS: The occurrence of ALS in biallelic or monoallelic GBA mutation carriers described here, in addition to common pathogenic pathways shared by GD1 and ALS, suggests that GBA variants could influence ALS risk. However, analyses of GBA variants in ALS cohorts did not reveal a meaningful association. Examination of larger cohorts and neuropathologic studies will be required to elucidate whether patients with GD1 are indeed at increased risk for ALS.

Parkinsonism in Patients with Neuronopathic (Type 3) Gaucher Disease: A Case Series.

BACKGROUND: The link between Parkinson's disease (PD), the second most common neurodegenerative disorder, and nonneuronopathic Gaucher disease (GD) is well established. Currently, PD is primarily associated with nonneuronopathic GD; however, with currently available treatments, patients with chronic neuronopathic GD, who historically had a shortened life span, are now living well into their 50s and beyond. CASES: We highlight 4 patients with chronic neuronopathic GD with parkinsonian features, describing their GD genotype and phenotype as well as the presentation and progression of their parkinsonism. Symptoms presented in their fourth or fifth decade of life, and include unilateral bradykinesia and/or tremor. Of the patients, 3 had cognitive impairment. The fourth patient has not shown cognitive decline 6 years after PD onset. CONCLUSION: This small series highlights that PD is not exclusively associated with nonneuronopathic GD and that as the chronic neuronopathic GD population ages, the clinical spectrum and heterogeneity of neurological manifestations may include parkinsonism.

Three cases of multi-generational Gaucher disease and colon cancer from an Ashkenazi Jewish family: A lesson for cascade screening.

Gaucher disease (GD) is one of the commonest lysosomal storage diseases that is inherited in an autosomal recessive manner and affects 1 in 50,000 to 100,000 people in the general population. The frequency is much higher (1 in 500 to 1000) in people of Ashkenazi Jewish heritage due to a founder effect. GD is caused by decreased or absent activity of ß-glucosidase with subsequent accumulation of the substrate glucosylceramide in macrophages due to genetic alterations in the GBA gene. These often accumulate in the spleen, liver and bone marrow. Three types exist, with type 1 being the most common, also referred to as non-neuronopathic GD. A broad clinical spectrum exists; patients of any age may manifest with hepatosplenomegaly, anaemia, thrombocytopenia, lung disease, bone abnormalities or may remain asymptomatic throughout their lifespan. Multi-generational disease does not usually occur because the risk of disease with each pregnancy, presuming both parents are carriers of the condition, is 25%. Herein, we report an Ashkenazi Jewish family with multi-generational GD type 1 and multigenerational colon cancer in the same three individuals, and reinforce the importance of cascade screening in families with genetic conditions.

Combined miglustat and enzyme replacement therapy in two patients with type 1 Gaucher disease: two case reports.

BACKGROUND: Intravenous enzyme replacement therapy is a first-line therapy for Gaucher disease type 1, and substrate reduction therapy represents an oral treatment alternative. Both enzyme replacement therapy and substrate reduction therapy are generally used as monotherapies in Gaucher disease. However, one randomized study and several case reports have described combination therapy over short time periods. CASE PRESENTATION: We report two female Gaucher disease type 1 patients of mainly Anglo-Saxon descent, where combined enzyme replacement therapy and miglustat substrate reduction therapy were administered to overcome refractory clinical symptoms. The first patient was diagnosed at age 17 and developed Gaucher disease-related bone manifestations that worsened despite starting imiglucerase enzyme replacement therapy. After switching to miglustat substrate reduction therapy, her bone symptoms improved, but she developed tremors and eventually switched back to enzyme replacement therapy. Miglustat was later recommenced in combination with ongoing enzyme replacement therapy due to continued bone pain, and her bone symptoms improved along with maintained visceral manifestations. Enzyme replacement therapy was subsequently tapered off and the patient has since been successfully maintained on miglustat. The second patient was diagnosed aged 3, and commenced imiglucerase enzyme replacement therapy aged 15. After 9 years on enzyme replacement therapy she switched to miglustat substrate reduction therapy and her core symptoms were maintained/stable for 3 years. Imiglucerase enzyme replacement therapy was later added as a boost to therapy and her symptoms were subsequently maintained over a 2.3-year period. However, miglustat was discontinued due to her relocation, necessitating an increase in enzyme replacement therapy dose. Overall, both patients benefited from combination therapy. CONCLUSION: While the majority of Gaucher disease type 1 patients will not need treatment with both substrate reduction therapy and enzyme replacement therapy, the current case reports demonstrate that judicious use of combination therapy may be of benefit in some cases.

Hair repigmentation associated with thalidomide use for the treatment of multiple myeloma.

A 75-year-old woman diagnosed with multiple myeloma in 2007 began treatment with monthly melphalan and prednisone for a total of 9 cycles in combination with thalidomide in 2009. The patient subsequently continued on thalidomide for long-term maintenance therapy. 3 years following initiation of thalidomide, the patient mentioned to her oncologist that her hair had become darker over the years. She attributed the change to thalidomide given the temporal relationship and progressive darkening over the course of therapy. The patient denies ever using any hair colouring treatments and had longstanding grey/white hair before beginning thalidomide in 2009. A case of hair repigmentation associated with the use of lenalidomide, a 4-amino-glutamyl analogue of thalidomide, in a patient with multiple myeloma was previously reported in the literature. We report herein the first case of hair repigmentation associated with the use of thalidomide, a related immunomodulatory drug.

Identification of novel splice site mutation IVS9 + 1(G > A) and novel complex allele G355R/R359X in Type 1 Gaucher patients heterozygous for mutation N370S.

Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. More than 350 mutations that cause Gaucher disease have been described to date. Novel mutations can potentially provide insight into the glucocerebrosidase structure-function relationship and biochemical basis of the disease. Here, we report the identification of two novel mutations in two unrelated patients with type I (non-neuronopathic) Gaucher disease: 1) a splice site mutation IVS9 + 1G > A; and (2) a complex allele (cis) G355R/R359X. Both patients have a common N370S mutation in the other allele. The splice site mutation results from an intronic base substitution (G to A, c.1328 + 1, g.5005) at the donor splice site of exon and intron 9. The complex allele results from two point mutations in exon 8 of glucocerebrosidase (G to C at c.1180, g.4396, and T to C at c. 1192, g.4408) substituting glycine by arginine (G355R) and arginine by a premature termination (R359X), respectively. In order to demonstrate that G355R/R359X are in cis arrangement, PCR-amplified glucocerebrosidase exon 8 genomic DNA from the patient was cloned into the vector pJET1.2 in Escherichia coli TOP10® strain. Out of the 15 clones that were sequence analyzed, 10 contained the normal allele sequence and 5 contained the complex allele G355R/R359X sequence showing both mutations in cis arrangement. Restriction fragment length polymorphism analysis using Hph1 restriction endonuclease digest was established for the IVS9 + 1G > A mutation for confirmation and efficient identification of this mutation in future patients. Past literature suggests that mutations affecting splicing patterns of the glucocerebrosidase transcript as well as mutations in Gaucher complex alleles are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings.

Long-term efficacy and safety results of taliglucerase alfa up to 36 months in adult treatment-naïve patients with Gaucher disease.

Taliglucerase alfa is an intravenous enzyme replacement therapy approved for treatment of type 1 Gaucher disease (GD), and is the first available plant cell-expressed recombinant therapeutic protein. Herein, we report long-term safety and efficacy results of taliglucerase alfa in treatment-naïve adult patients with GD. Patients were randomized to receive taliglucerase alfa 30 or 60 U/kg every other week, and 23 patients completed 36 months of treatment. Taliglucerase alfa (30 U/kg; 60 U/kg, respectively) resulted in mean decreases in spleen volume (50.1%; 64.6%) and liver volume (25.6%; 24.4%) with mean increases in hemoglobin concentration (16.0%; 35.8%) and platelet count (45.7%; 114.0%), and mean decreases in chitotriosidase activity (71.5%; 82.2%). All treatment-related adverse events were mild to moderate in intensity and transient. The most common adverse events were nasopharyngitis, arthralgia, upper respiratory tract infection, headache, pain in extremity, and hypertension. These 36-month results of taliglucerase alfa in treatment-naïve adult patients with GD demonstrate continued improvement in disease parameters with no new safety concerns. These findings extend the taliglucerase alfa clinical safety and efficacy dataset. www.clinicaltrials.gov identifier NCT00705939. Am. J. Hematol. 91:656-660, 2016. © 2016 Wiley Periodicals, Inc.

Enzyme replacement therapy with taliglucerase alfa: 36-month safety and efficacy results in adult patients with Gaucher disease previously treated with imiglucerase.

Taliglucerase alfa is the first available plant cell-expressed human recombinant therapeutic protein. It is indicated for treatment of patients with type 1 Gaucher disease (GD) in adult and pediatric patients in several countries. Study PB-06-002 examined the safety and efficacy of taliglucerase alfa for 9 months in patients who previously received imiglucerase. The results of adult patients from Study PB-06-002 who continued receiving taliglucerase alfa in extension Study PB-06-003 for up to 36 months are reported here. Eighteen patients received at least one dose of taliglucerase alfa in Study PB-06-003; 10 patients completed 36 total months of therapy, and four patients who transitioned to commercial drug completed 30-33 months of treatment. In patients who completed 36 total months of treatment, mean percent (±standard error) changes from baseline/time of switch to taliglucerase alfa to 36 months were as follows: hemoglobin concentration, -1.0% (±1.9%; n = 10); platelet count, +9.3% (±9.8%; n = 10); spleen volume measured in multiples of normal (MN), -19.8% (±9.9%; n = 7); liver volume measured in MN, +0.9% (±5.4%; n = 8); chitotriosidase activity, -51.5% (±8.1%; n = 10); and CCL18 concentration, -36.5 (±8.0%; n = 10). Four patients developed antidrug antibodies, including one with evidence of neutralizing activity in vitro. All treatment-related adverse events were mild or moderate and transient. The 36-month results of switching from imiglucerase to taliglucerase alfa treatment in adults with GD provide further data on the clinical safety and efficacy of taliglucerase alfa beyond the initial 9 months of the original study. www.clinicaltrials.gov identifier NCT00705939. Am. J. Hematol. 91:661-665, 2016. © 2016 Wiley Periodicals, Inc.

A double-blind, randomized, placebo-controlled trial studying the effects of Saccharomyces boulardii on the gastrointestinal tolerability, safety, and pharmacokinetics of miglustat.

BACKGROUND: Gastrointestinal (GI) disturbances such as diarrhea and flatulence are the most frequent adverse effects associated with miglustat therapy in type 1 Gaucher disease (GD1) and Niemann-Pick disease type C (NP-C), and the most common recorded reason for stopping treatment during clinical trials and in clinical practice settings. Miglustat-related GI disturbances are thought to arise from the inhibition of intestinal disaccharidases, mainly sucrase isomaltase. We report the effects of a co-administered dietary probiotic, S. boulardii, on the GI tolerability of miglustat in healthy adult subjects. METHODS: In a double-blind, placebo-controlled, two-period, two-treatment cross-over trial, healthy adult male and female subjects were randomly allocated to treatment sequences, A-B and B-A (treatment A - miglustat 100 mg t.i.d. + placebo; treatment B - miglustat 100 mg t.i.d. + S. boulardii [500 mg, b.i.d.]). GI tolerability data were collected in patient diaries. The primary endpoint was the total number of 'diarrhea days' (≥3 loose stools within a 24-h period meeting Bristol Stool Scores [BSS] 6-7) based on WHO criteria. Secondary endpoints comprised numerous other diarrhea and GI tolerability indices. RESULTS: Twenty-one subjects received randomized therapy in each treatment sequence (total N = 42), and overall, 37 (88 %) subjects completed the study. The total number of diarrhea days was <1.5 for both treatment sequences, and approximately 60 % of subjects did not experience diarrhea during either treatment period. The mean (SD) number of diarrhea days was lower with miglustat + S. boulardii (0.8 [2.4] days) than with miglustat + placebo (1.3 [2.4] days), but the paired treatment difference was not statistically significant (-0.5 [2.4] days; p = 0.159). However, a significant treatment difference (-0.7 [1.9]; p < 0.05) was identified after post hoc exclusion of a clear outlier who had a very high number of diarrhea days (n = 13) and inconsistent GI tolerability reporting. The incidence of the GI AEs was higher with miglustat + placebo (82 %) than with miglustat + S. boulardii (73 %). There were no between-treatment differences in miglustat pharmacokinetics. CONCLUSIONS: Although the primary endpoint was not met, the results of the post-hoc analysis suggest that co-administration of miglustat with S. boulardii might improve GI tolerability.

Evaluation of disease burden and response to treatment in adults with type 1 Gaucher disease using a validated disease severity scoring system (DS3).

BACKGROUND: GD1-DS3 is an integrated assessment of type 1 Gaucher disease (GD1) burden based on bone, hematologic and visceral domains. We investigated this disease severity scoring system (DS3) methodology for initial assessment, long-term follow-up and evaluation of treatment responses. METHODS: We enrolled 133 treated adult GD1 patients. Baseline DS3 scores were calculated near the initial treatment date and patients stratified by severity as marked (DS3 6.00-19.00), moderate (DS3 3.00-5.99), mild (DS3 < 3.00). Follow-up scores were calculated annually. Minimal clinically important improvement (MCII), is defined as ΔDS3 of -3.1. PATIENT CHARACTERISTICS: N370S was the most common allele (118 patients had at least one), 52 were N370S/N370S (48/52 were Ashkenazi Jews), N370S/L444P was the most common genotype among non-Jews. Median age of treatment: 45 years; median follow-up: 14 years. Baseline DS3 scores: Patients with marked disease (N = 58; median 7.84) were least likely to be N370S homozygous (19 %) and most likely to have had splenectomy (53 %), early age at diagnosis (median 18 years) and major pre-treatment bone pathology (76 %). Among patients with moderate disease (N = 53; median 4.33), 49 % were N370S/N370S, 15.1 % had splenectomy and 17 % had major bone disease. Median age at diagnosis: 32 years. No patient with mild disease (N = 22; median 2.4) had splenectomy or major skeletal disease. Median age at diagnosis: 40 years. 68 % were N370S homozygous. Response to treatment: Health-state transitions occurred primarily during the early treatment years. At Year 5, among 48 evaluable patients with marked baseline disease, eight were unchanged in severity status whereas 40 had MCII of varying degrees with 11 scored as mild. Among 42 evaluable moderate patients, none worsened, 16 remained moderate and 26 improved to mild. Among 16 evaluable mild patients, 14 remained so and 2 had DS3 scores in the low moderate range. CONCLUSIONS: DS3 is effective for assessing disease burden in GD1 and for monitoring response. ERT was associated with MCII in DS3 scores in patients with high severity. Nevertheless, despite better DS3 scores with treatment, GD1 patients especially those with splenectomy and pre-treatment bone pathology, continued to have bone complications.

Effect of oral eliglustat on splenomegaly in patients with Gaucher disease type 1: the ENGAGE randomized clinical trial.

IMPORTANCE: Gaucher disease type 1 is characterized by hepatosplenomegaly, anemia, thrombocytopenia, and skeletal disease. A safe, effective oral therapy is needed. OBJECTIVE: To determine whether eliglustat, a novel oral substrate reduction therapy, safely reverses clinical manifestations in untreated adults with Gaucher disease type 1. DESIGN, SETTING, AND PARTICIPANTS: Phase 3, randomized, double-blind, placebo-controlled trial conducted at 18 sites in 12 countries from November 2009 to July 2012 among eligible patients with splenomegaly plus thrombocytopenia and/or anemia. Of 72 patients screened, 40 were enrolled. INTERVENTIONS: Patients were stratified by spleen volume and randomized 1:1 to receive eliglustat (50 or 100 mg twice daily; n = 20) or placebo (n = 20) for 9 months. MAIN OUTCOMES AND MEASURES: The primary efficacy end point was percentage change in spleen volume in multiples of normal from baseline to 9 months; secondary efficacy end points were change in hemoglobin level and percentage changes in liver volume and platelet count. RESULTS: All patients had baseline splenomegaly and thrombocytopenia (mostly moderate or severe), most had mild or moderate hepatomegaly, and 20% had mild anemia. Least-square mean spleen volume decreased by 27.77% (95% CI, -32.57% to -22.97%) in the eliglustat group (from 13.89 to 10.17 multiples of normal) vs an increase of 2.26% (95% CI, -2.54% to 7.06%) in the placebo group (from 12.50 to 12.84 multiples of normal) for an absolute treatment difference of -30.03% (95% CI, -36.82% to -23.24%; P < .001). For the secondary end points, the least-square mean absolute differences between groups all favored eliglustat, with a 1.22-g/dL increase in hemoglobin level (95% CI, 0.57-1.88 g/dL; P < .001), 6.64% decrease in liver volume (95% CI, -11.37% to -1.91%; P = .007), and 41.06% increase in platelet count (95% CI, 23.95%-58.17%; P < .001). No serious adverse events occurred. One patient in the eliglustat group withdrew (non-treatment related); 39 of the 40 patients transitioned to an open-label extension study. CONCLUSIONS AND RELEVANCE: Among previously untreated adults with Gaucher disease type 1, treatment with eliglustat compared with placebo for 9 months resulted in significant improvements in spleen volume, hemoglobin level, liver volume, and platelet count. The clinical significance of these findings is uncertain, and more definitive conclusions about clinical efficacy and utility will require comparison with the standard treatment of enzyme replacement therapy as well as longer-term follow-up. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00891202.

A Phase 3, multicenter, open-label, switchover trial to assess the safety and efficacy of taliglucerase alfa, a plant cell-expressed recombinant human glucocerebrosidase, in adult and pediatric patients with Gaucher disease previously treated with imiglucerase.

Taliglucerase alfa is a ß-glucosidase enzyme replacement therapy (ERT) approved in the US and other countries for the treatment of Gaucher disease (GD) in adults and is approved in pediatric and adult patients in Australia and Canada. It is the first approved plant cell-expressed recombinant human protein. A Phase 3, multicenter, open-label, 9-month study assessed safety and efficacy of switching to taliglucerase alfa in adult and pediatric patients with GD treated with imiglucerase for at least the previous 2years. Patients with stable disease were offered taliglucerase alfa treatment using the same dose (9-60U/kg body weight) and regimen of administration (every 2weeks) as imiglucerase. This report summarizes results from 26 adult and 5 pediatric patients who participated in the trial. Disease parameters (spleen and liver volumes, hemoglobin concentration, platelet count, and biomarker levels) remained stable through 9months of treatment in adults and children following the switch from imiglucerase. All treatment-related adverse events were mild or moderate in severity and transient in nature. Exploratory parameters of linear growth and development showed positive outcomes in pediatric patients. These findings provide evidence of the efficacy and safety profile of taliglucerase alfa as an ERT for GD in patients previously treated with imiglucerase. This trial was registered at www.clinicaltrials.gov as # NCT00712348.

Two novel mutations in glucocerebrosidase, C23W and IVS7-1 G>A, identified in Type 1 Gaucher patients heterozygous for N370S.

Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. There have been nearly 300 mutations described to date. Novel mutations can potentially provide insight into the biochemical basis of the disease. Two novel mutations are described in two Type 1 Gaucher patients with N370S compound heterozygosity; a point mutation that causes an amino acid substitution at cysteine residue 23 for tryptophan, and a second point mutation within the splicing element at the 3' end of intron 7. Both mutations were identified by PCR amplification and sequence analysis of patient glucocerebrosidase genomic DNA. Restriction fragment length polymorphism analysis was established for both novel mutations for efficient identification in future patients. Past literature suggests that mutations affecting cysteine residues involved in disulfide bridges, as well as mutations affecting splicing patterns of the glucocerebrosidase transcript, are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings.

Evaluation of miglustat as maintenance therapy after enzyme therapy in adults with stable type 1 Gaucher disease: a prospective, open-label non-inferiority study.

BACKGROUND: Previous studies have provided equivocal data on the use of miglustat as maintenance therapy in Gaucher disease type 1. We report findings from a clinical trial evaluating the effects of miglustat treatment in patients with stable type 1 Gaucher disease after enzyme therapy. METHODS: Adult type 1 Gaucher disease patients stabilized during at least 3 years of previous enzyme therapy were included in this 2-year, prospective, open-label non-inferiority study. The primary endpoint was percent change from baseline in liver volume. Secondary endpoints included changes in spleen volume, hemoglobin concentration and platelet count. RESULTS: Forty-two patients were enrolled (mean±SD age, 45.1±12.7 years; previous enzyme therapy duration 9.5±4.0 years). Median (range) exposure to miglustat 100 mg t.i.d. was 658 (3-765) days. Twenty-one patients discontinued treatment prematurely; 13 due to adverse events, principally gastrointestinal. The upper 95% confidence limit of mean percent change in liver volume from baseline to end of treatment was below the non-inferiority margin of 10% (-1.1%; 95%CI -6.0, 3.9%). Mean (95%CI) changes in spleen volume, hemoglobin concentration and platelet count were 102 (24,180) mL, -0.95 (-1.38, -0.53) g/dL and -44.1 (-57.6, -30.7) ×109/L, respectively. CONCLUSIONS: The primary efficacy endpoint was met; overall there was no change in liver volume during 24 months of miglustat therapy. Several patients showed a gradual deterioration in some disease manifestations, suggesting that miglustat could maintain clinical stability, but not in all patients. Miglustat demonstrated a predictable profile of safety and tolerability that was consistent with that reported in previous clinical trials and experience in clinical practice. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT00319046.

Pivotal trial with plant cell-expressed recombinant glucocerebrosidase, taliglucerase alfa, a novel enzyme replacement therapy for Gaucher disease.

Taliglucerase alfa (Protalix Biotherapeutics, Carmiel, Israel) is a novel plant cell-derived recombinant human ß-glucocerebrosidase for Gaucher disease. A phase 3, double-blind, randomized, parallel-group, comparison-dose (30 vs 60 U/kg body weight/infusion) multinational clinical trial was undertaken. Institutional review board approvals were received. A 9-month, 20-infusion trial used inclusion/exclusion criteria in treatment-naive adult patients with splenomegaly and thrombocytopenia. Safety end points were drug-related adverse events: Ab formation and hypersensitivity reactions. Primary efficacy end point was reduction in splenic volume measured by magnetic resonance imaging. Secondary end points were: changes in hemoglobin, hepatic volume, and platelet counts. Exploratory parameters included biomarkers and bone imaging. Twenty-nine patients (11 centers) completed the protocol. There were no serious adverse events; drug-related adverse events were mild/moderate and transient. Two patients (6%) developed non-neutralizing IgG Abs; 2 other patients (6%) developed hypersensitivity reactions. Statistically significant spleen reduction was achieved at 9 months: 26.9% (95% confidence interval [CI]: -31.9, -21.8) in the 30-unit dose group and 38.0% (95% CI: -43.4, -32.8) in the 60-unit dose group (both P < .0001); and in all secondary efficacy end point measures, except platelet counts at the lower dose. These results support safety and efficacy of taliglucerase alfa for Gaucher disease.

Homozygous N396T mutation in Gaucher disease: Portuguese sisters with markedly different phenotypes.

Gaucher disease (GD) is characterized by reduced activity of glucocerebrosidase leading to complications in the reticuloendothelial system. N396T, a rarer mutation of the glucocerebrosidase gene, has been encountered in Portuguese populations and has generally been associated with milder phenotypes. This report presents brief histories of two Portuguese sisters, both with homozygous N396T mutations. These patients are phenotypically very different despite the fact that in both patients residual enzyme activity is very low. The case of patient 1 is complicated by comorbid diabetes mellitus and human immunodeficiency virus (HIV) infection. Enzyme replacement therapy (ERT) improved this patient's clinical picture sufficiently to enable antiretroviral treatment to proceed for the HIV. This report demonstrates the poor correlation of clinical GD with genotype as well as with residual enzyme activity. It further illustrates how treatment of the underlying GD with ERT improved symptoms allowing for antiretroviral therapy thereby improving both the GD and HIV.