A disease severity scoring system for children with type 1 Gaucher disease

Current and emerging pharmacotherapy for Gaucher disease in pediatric populations

INTRODUCTION

The past decades have witnessed a remarkable improvement in the health of patients with Gaucher disease, the inherited deficiency of the lysosomal enzyme glucocerebrosidase, resulting from the availability of enzyme replacement and substrate reduction therapies. Especially in pediatric populations, early diagnosis and initiation of treatment is essential to achieving optimal outcomes.

AREAS COVERED

The authors review the literature pertaining to the effectiveness of currently available therapies and describe new pharmacotherapies under development, especially for young patients.

EXPERT OPINION

For pediatric patients with non-neuronopathic Gaucher disease, there may be new therapeutic options on the horizon in the form of gene therapy or small molecule glucocerebrosidase chaperones. These have the potential to result in a cure for systemic disease manifestations and/or to reduce the cost and convenience of treatment. For children with neuronopathic Gaucher disease, the challenge of targeting therapy to the central nervous system is being explored through new modalities including brain-targeted gene therapy, in-utero therapy, brain-penetrant small molecule chaperones, and other methods that convey enzyme across the blood-brain barrier. Indeed, these are exciting times for both pediatric patients with Gaucher disease and those with other lysosomal storage disorders.

The N370S/R496H genotype in type 1 Gaucher disease - Natural history and implications for pre symptomatic diagnosis and counseling

Type 1 Gaucher disease (GD1) patients with the N370S/R496H (N409S/R535H) genotype are increasingly identified through carrier and newborn screening panels. However, limited information is available on the phenotype associated with this genotype. Here, we report our experience with 14 patients with this genotype. Our data suggests that most patients with N370S/R496H present with mild manifestations and often do not require treatment. This information is important for counseling newly diagnosed patients and GD1 carrier couples.

Imaging of non-neuronopathic Gaucher disease: recent advances in quantitative imaging and comprehensive assessment of disease involvement

Gaucher disease is an inherited metabolic disorder resulting in deficiency of lysosomal enzyme β-glucocerebrosidase causing the accumulation of abnormal macrophages (“Gaucher cells”) within multiple organs, most conspicuously affecting the liver, spleen, and bone marrow. As the most common glycolipid metabolism disorder, it is important for radiologists encountering these patients to be familiar with advances in imaging of organ and bone marrow involvement and understand the role of imaging in clinical decision-making. The recent advent of commercially available, reliable, and reproducible quantitative MRI acquisitions to measure fat fractions prompts revisiting the role of quantitative assessment of bone marrow involvement. This manuscript reviews the diverse imaging manifestations of Gaucher disease and discusses more optimal quantitative approaches to ascertain solid organ and bone marrow involvement with an emphasis on future applications of other quantitative methods including elastography.

Diagnosis features of pediatric Gaucher disease patients in the era of enzymatic therapy, a national-base study from the Spanish Registry of Gaucher Disease

BACKGROUND

The enzymatic replacement therapy (ERT) availability for Gaucher disease (GD) has changed the landscape of the disease, several countries have screening programs. These actions have promoted the early diagnosis and avoided many complications in pediatric patients. In Spain ERT has been available since 1993 and 386 patients have been included in the Spanish Registry of Gaucher Disease (SpRGD). The aim of this study is to analyze the impact of ERT on the characteristics at time of diagnosis and initial complications in pediatric Gaucher disease patients.

AIM

To analyze the impact of ERT on the characteristics at time of diagnosis and initial complications in pediatric Gaucher disease patients.

METHODS

A review of data in SpRGD from patients' diagnosed before 18 years old was performed. The cohort was split according the year of diagnosis (≤1994, cohort A; ≥1995, cohort B).

RESULTS

A total of 98 pediatric patients were included, GD1: 80, GD3: 18; mean age: 7.2 (0.17-16.5) years, 58 (59.2%) males and 40 (40.8%) females. Forty-five were diagnosed ≤ 1994 and 53 ≥ 1995. Genotype: N370S/N370S: 2 (2.0%), N370S/L444P: 27 (27.5%), N370S/other: 47 (48%), L444P/L444P: 7 (7.1%), L444P/D409H: 2 (2.0%), L444P/other: 3 (6.2%), other/other: 10 (10.2%). The mean age at diagnosis was earlier in patients diagnosed after 1995 (p < 0.001) and different between the subtypes, GD1: 8.2 (0.2-16.5) years and GD3: 2.8 (0.17-10.2) years (p < 0.001). There were more severe patients in the group diagnosed before 1994 (p = 0.045) carrying L444P (2), D409H (2), G377S (1), G195W (1) or the recombinant mutation. The patients' diagnosed ≤1994 showed worse cytopenias, higher chance of bone vascular complications at diagnosis and previous spleen removal. The patients started ERT at a median time after diagnosis of 5.2 years [cohort A] and 1.6 years [cohort B] (p < 0.001).

CONCLUSIONS

The early diagnosis of Gaucher disease in the era of ERT availability has permitted to reduce the incidence of severe and irreversible initial complication in pediatric patients, and this has permitted better development of these patients. This is the largest pediatric cohort from a national registry.

Early manifestations of type 1 Gaucher disease in presymptomatic children diagnosed after parental carrier screening

PURPOSE

The overall published experience with pediatric type 1 Gaucher disease (GD1) has been based on ascertainment through clinical presentation of the disease. We describe the longitudinal follow-up in a presymptomatic pediatric cohort.

METHODS

The cohort includes children diagnosed with GD1, either prenatally or postnatally by molecular genetic testing, and followed for clinical care at our center from 1998 to 2016. All patients' parents were GBA mutation carriers identified through carrier screening programs. Longitudinal clinical, laboratory, and imaging data were obtained through chart review.

RESULTS

Thirty-eight patients aged 1-18 years (mean at last visit 6.9 ± 4.1 years) were followed, including 32 p.N409S homozygotes and 6 p.N409S/p.R535H compound heterozygotes. At the last evaluation, a minority had hematological (5%), bone (15%), or linear growth (19%) issues. Only 12% had splenomegaly and 74% had moderate hepatomegaly. Chitotriosidase activity varied widely (6-5,640 nmol/hour/ml) and generally increased with age. Pediatric Gaucher severity scores (GSS) remained stable and within the mild-disease range for most (95%). Treatment for progressive disease during this period was recommended for four children.

CONCLUSION

Most children with the p.N409S/p.N409S and p.N409S/p.R535H GD1 genotypes have minimal disease manifestations and progression during childhood and can be monitored using limited assessments. Those with other mutations may require additional monitoring. These data are valuable for newborn screening and counseling.Genet Med advance online publication 13 October 2016.

Understanding the natural history of Gaucher disease

Gaucher disease is a rare and extraordinarily heterogeneous inborn error of metabolism that exhibits diverse manifestations, a broad range of age of onset of symptoms, and a wide clinical spectrum of disease severity, from lethal disease during infancy to first age of onset of symptoms in octogenarians. Before the advent of the International Collaborative Gaucher Group (ICGG) Gaucher Registry, the understanding of the natural history and phenotypic range of Gaucher disease was based on isolated case reports and small case series. Limited data hindered understanding of the full spectrum of the disease leading to some early misconceptions about Gaucher disease, notably, that nonneuronopathic (type 1) disease was a disease of adults only. The global scope of the ICGG Gaucher Registry, with its vast body of longitudinal data, has enabled a real appreciation of both the phenotypic spectrum of Gaucher disease and its natural history. This body of evidence represents the foundation for accurate assessment of the response to specific therapies for Gaucher disease and to the development of standard-of-care to monitor disease activity. Here, we outline the key developments in delineating the natural history of this highly complex disease and role of the ICGG Gaucher Registry in this effort.

Evolução do estado nutricional na doença de Gaucher tipo I em tratamento com reposição enzimática - relato de dois casos

Resumo Introdução: a doença de Gaucher é um erro do metabolismo enzimático que leva ao acúmulo de glicocerebrosídeo nas células, o que caracteriza os sinais e sintomas da doença. No momento do diagnóstico, além de outros sinais e sintomas, é observado retardo no crescimento em crianças e adolescentes. O tratamento é realizado por meio de reposição enzimática, que pode ocasionar ganho de peso no paciente pela diminuição do metabolismo energético. Descrição: dois irmãos com diagnóstico de doença de Gaucher tipo I foram avaliados antes de iniciarem a reposição enzimática e depois a cada 2 meses de tratamento, por um período de 6 meses. A composição corporal foi avaliada por impedância bioelétrica, que avaliou a quantidade de massa livre de gordura e massa de gordura; o consumo energético e a relação de macronutrientes foram avaliados por registro alimentar de 3 dias. Discussão: os dois pacientes apresentavam baixa estatura para idade ao diagnóstico e tiveram aumento de massa de gordura durante o tratamento, sendo que um paciente também apresentou aumento da massa livre de gordura. O consumo energético e a relação de macronutrientes mantiveram-se semelhantes durante todo o período de acompanhamento para ambos os pacientes.

Bone disease in patients with Gaucher disease

Gaucher disease is an inborn error of metabolism due to a deficiency of the lysosomal enzyme glucocerebrosidase. As a result of this deficiency, the substrate glucocerebroside accumulates in the liver, spleen, bone and bone marrow. Bone involvement can lead to abnormalities in bone growth, bone remodeling, bone infarcts, aseptic necrosis, osteonecrosis, increased fracture risk and lytic bone lesions. Patients may experience bone pain and bone crises related to bone infarcts. There is evidence of abnormal bone metabolism in both bone resorption and bone formation based upon biochemical abnormalities found in patients. In addition, both immunological and coagulation abnormalities have in part been implicated in the causation of bone disease. Treatment with enzyme replacement therapy and substrate reduction therapy has led to improvement in both the symptoms and the radiographic abnormalities seen in these patients. It is unknown whether these treatments lower fracture risk.