A review of type 3 Gaucher disease: unique neurological manifestations and advances in treatment

Gaucher disease (GD) is a rare lysosomal storage disease that is caused by mutations in the GBA gene. It is classified into three main phenotypes according to the patient's clinical presentation. Of these, chronic neuronopathic GD (GD3) is characterized by progressive neurological damage. Understanding the unique neurological manifestations of GD3 has important diagnostic and therapeutic implications. Our article summarizes the neurological symptoms specific to GD3 and related therapeutic advances, and it highlights the relevance of the gene to clinical symptoms, so as to provide a reference for the diagnosis and treatment of GD3.

Thirty-year clinical outcomes after haematopoietic stem cell transplantation in neuronopathic Gaucher disease

Background

Neuronopathic Gaucher Disease (nGD) describes the condition of a subgroup of patients with the Lysosomal Storage Disorder (LSD), Gaucher disease with involvement of the central nervous system (CNS) which results from inherited deficiency of β-glucosylceramidase. Although systemic manifestations of disease are now corrected by augmentation with macrophage-targeted therapeutic enzyme (enzyme replacement therapy, ERT), neurological disease progresses unpredictably as a result of failure of therapeutic enzyme to cross the blood–brain barrier (BBB). Without therapy, the systemic and neurological effects of the disease progress and shorten life: investigators, principally in Sweden and the UK, pioneered bone marrow transplantation (BMT; Haematopoietic Stem Cell Transplantation HSCT) to supply healthy marrow-derived macrophages and other cells, to correct the peripheral disease. Here we report the first long-term follow-up (over 20 years in all cases) of nine patients in the UK and Sweden who underwent HSCT in the 1970s and 1980s. This retrospective, multicentre observational study was undertaken to determine whether there are neurological features of Gaucher disease that can be corrected by HSCT and the extent to which deterioration continues after the procedure. Since intravenous administration of ERT is approved for patients with the neuronopathic disease and ameliorates many of the important systemic manifestations but fails to correct the neurological features, we also consider the current therapeutic positioning of HSCT in this disorder.

Results

In the nine patients here reported, neurological disease continued to progress after transplantation, manifesting as seizures, cerebellar disease and abnormalities of tone and reflexes.

Conclusions

Although neurological disease progressed in this cohort of patients, there may be a future role for HSCT in the treatment of nGD. The procedure has the unique advantage of providing a life-long source of normally functioning macrophages in the bone marrow, and possibly other sites, after a single administration. HSCT moreover, clearly ameliorates systemic disease and this may be advantageous—especially where sustained provision of high-cost ERT cannot be guaranteed. Given the remaining unmet needs of patients with neuronopathic Gaucher disease and the greatly improved safety profile of the transplant procedure, HSCT could be considered to provide permanent correction of systemic disease, including bone disease not ameliorated by ERT, when combined with emerging therapies directed at the neurological manifestations of disease; this could include ex-vivo gene therapy approaches.

Characteristics of 26 patients with type 3 Gaucher disease: A descriptive analysis from the Gaucher Outcome Survey

The Gaucher Outcome Survey (GOS) is an international disease-specific registry established in 2010 for patients with a confirmed diagnosis of Gaucher disease (GD), regardless of GD type or treatment status. Historically, there has been a limited understanding of type 3 GD (GD3) and its natural history in patients irrespective of their treatment status. Here, we describe the disease characteristics of patients with GD3 enrolled in GOS. As of October 2015, 1002 patients had been enrolled, 26 of whom were reported as GD3. The majority of patients with GD3 were from the US (13; 50.0%), seven (26.9%) were from the UK, three (11.5%) from Israel, and three (11.5%) from Brazil. No patients were of Ashkenazi Jewish origin. Median age of symptom onset was 1.4 (interquartile range: 0.5–2.0) years. The most common GBA1 mutation genotype was L444P/L444P, occurring in 16 (69.6%) of 23 patients who had genotyping information available. Nine patients reported a family history of GD (any type). Of 21 patients with treatment status information, 20 (95.2%) had received GD-specific treatment at any time, primarily imiglucerase (14 patients) and/or velaglucerase alfa (13 patients). Hemoglobin concentrations and platelet counts at GOS entry were within normal ranges for most patients, and there were no reports of severe hepatomegaly or of splenomegaly in non-splenectomized patients, most likely indicative of the effects of treatment received prior to GOS entry. This analysis provides information on the characteristics of patients with GD3 that could be used as the baseline for longitudinal follow-up of these patients.