The diagnosis and management of Gaucher disease in pediatric patients: Where do we go from here?

Gaucher disease (GD) is an autosomal recessive inherited lysosomal storage disease that often presents in early childhood and is associated with damage to multiple organ systems. Many challenges associated with GD diagnosis and management arise from the considerable heterogeneity of disease presentations and natural history. Phenotypic classification has traditionally been based on the absence (in type 1 GD) or presence (in types 2 and 3 GD) of neurological involvement of varying severity. However, patient management and prediction of prognosis may be best served by a dynamic, evolving definition of individual phenotype rather than by a rigid system of classification. Patients may experience considerable delays in diagnosis, which can potentially be reduced by effective screening programs; however, program implementation can involve ethical and practical challenges. Variation in the clinical course of GD and an uncertain prognosis also complicate decisions concerning treatment initiation, with differing stakeholder perspectives around efficacy and acceptable cost/benefit ratio. We review the challenges faced by physicians in the diagnosis and management of GD in pediatric patients. We also consider future directions and goals, including acceleration of accurate diagnosis, improvements in the understanding of disease heterogeneity (natural history, response to treatment, and prognosis), the need for new treatments to address unmet needs for all forms of GD, and refinement of the tools for monitoring disease progression and treatment efficacy, such as specific biomarkers.

Newborn Screening for Pompe Disease: Pennsylvania Experience.

Pennsylvania started newborn screening for Pompe disease in February 2016. Between February 2016 and December 2019, 531,139 newborns were screened. Alpha-Glucosidase (GAA) enzyme activity is measured by flow-injection tandem mass spectrometry (FIA/MS/MS) and full sequencing of the GAA gene is performed as a second-tier test in all newborns with low GAA enzyme activity [<2.10 micromole/L/h]. A total of 115 newborns had low GAA enzyme activity and abnormal genetic testing and were referred to metabolic centers. Two newborns were diagnosed with Infantile Onset Pompe Disease (IOPD), and 31 newborns were confirmed to have Late Onset Pompe Disease (LOPD). The incidence of IOPD + LOPD was 1:16,095. A total of 30 patients were compound heterozygous for one pathogenic and one variant of unknown significance (VUS) mutation or two VUS mutations and were defined as suspected LOPD. The incidence of IOPD + LOPD + suspected LOPD was 1: 8431 in PA. We also found 35 carriers, 15 pseudodeficiency carriers, and 2 false positive newborns.

Postnatal Pancraniosynostosis in a Patient With Infantile Hypophosphatasia.

Hypophosphatasia is a rare metabolic bone disorder that predisposes patients to craniosynostosis. Typically, patients born with hypophosphatasia will exhibit fused cranial sutures at birth. This is the first reported case of delayed onset of pancraniosynostosis in a patient with infantile hypophosphatasia. The severity of onset and delayed presentation in this patient are of interest and should give pause to those care providers who treat and evaluate patients with hypophosphatasia.

Correlation of surrogate markers of Gaucher disease. Implications for long-term follow up of enzyme replacement therapy.

BACKGROUND: The excessive storage of cellular debris in the lysosomal storage disorders triggers a variety of cellular responses. Some of these responses are maladaptative and result in the pathology of these diseases. To some extent, cellular responses are specific to the stored material, which influences the pathophysiology of the disease and results in some of its characteristic features. METHODS: A large body of data has been collected for three biochemical (surrogate) markers of Gaucher Disease: angiotensin converting enzyme (ACE), tartrate-resistant acid phosphatase (TRAP) and chitotriosidase (CHITO) using currently available enzyme analysis. Follow up data was gathered in a group of 18 patients. RESULTS: The three markers are correlated between each other and are useful indicators of the disease progress and its response to enzyme replacement therapy (ERT). Retrospective analysis of clinical records and comparison of chitotriosidase values with the baseline Severity Score Index (SSI) allowed prediction of the response patterns for this marker when long-term ERT (>24 months) was evaluated. CONCLUSIONS: The less severely affected patients are more likely to normalize their chitotriosidase activities after long term ERT.