Gaucher disease (GD) is a rare lysosomal storage disorder characterized by multisystemic involvement. With the advent of enzyme replacement therapy (ERT), patient survival has improved, revealing new long-term complications. We report a case of a 4-year-old male with severe neurovisceral GD who developed protein-losing enteropathy (PLE) secondary to mesenteric lymphadenopathy, despite ERT starting in the neonatal period. Furthermore, we review the literature related to this rare complication. The patient presented with severe recurrent diarrhea, abdominal distension, weight loss, and malnutrition. Abdominal CT revealed multiple enlarged mesenteric lymph nodes with calcification. Laboratory findings showed lymphopenia and increased fecal alpha-1-antitrypsin. Other causes of diarrhea were excluded. Treatment with a specific diet (high-protein, MCT-enriched) and a course of budesonide resulted in persistent clinical improvement and normalization of laboratory parameters. This case highlights the emergence of gastrointestinal complications in patients with neurovisceral GD on long-term ERT, particularly the development of PLE due to mesenteric lymphadenopathy. It underscores the need for vigilance in monitoring GD patients for such complications and demonstrates the potential efficacy of dietary interventions and anti-inflammatory therapy in managing PLE in this context. The case also emphasizes the limitations of current ERT in addressing all aspects of GD, particularly in sequestered sites like lymph nodes, and calls for new therapeutic strategies to address these challenges.

Gaucher disease (GD), a lysosomal storage disorder, results from the accumulation of glycosphingolipids due to deficient lysosomal glucocerebrosidase activity. This pathological accumulation triggers immune activation, which paradoxically induces UDPglucose ceramide glucosyltransferase (UGCG), further exacerbating the metabolic defect. Eliglustat, a highly specific inhibitor of UGCG, functions as a substrate reduction therapy (SRT) and has demonstrated efficacy in reversing GD manifestations in clinical trials and real-world settings. Despite its established safety profile, preclinical studies have shown that supratherapeutic concentrations of eliglustat can inhibit ion channels involved in cardiac electrophysiology. However, pharmacogenomic-guided dosing ensures therapeutic efficacy while maintaining a wide safety margin, minimizing such risks. Nevertheless, lingering concerns regarding cardiac safety have persisted, particularly in patients with preexisting cardiac comorbidities. We report a single-center experience of eliglustat use in 13 patients with type 1 Gaucher disease (GD1) and concurrent cardiac comorbidities. Patients underwent standard cardiac evaluations, including electrocardiogram (EKG) with QTc interval assessment and echocardiogram. Eliglustat dosing was guided by CYP2D6 metabolizer status, and potential drug-drug interactions (DDIs) were carefully monitored. Cardiac comorbidities included prior myocardial infarction (n = 2), aortic stenosis (n = 2), atrial fibrillation (n = 2), Wolff-Parkinson-White syndrome (n = 1), pericarditis (n = 1), premature ventricular complexes (n = 2), severe pulmonary arterial hypertension with right heart strain (n = 1), mitral annular calcification with diastolic dysfunction (n = 1), and mildly prolonged QTc interval (n = 1). No patients experienced arrhythmia, QTc prolongation, or arrhythmia-related symptoms. Treatment discontinuation was not required. All patients achieved expected therapeutic outcomes, as evidenced by serial reductions in glucosylsphingosine (GlcSph) levels and other disease indicators. This study represents the first real-world clinical evidence evaluating Eliglustat's cardiac safety in a high-risk GD1 population. Unlike prior theoretical concerns derived from in vitro ion channel studies, our findings demonstrate that Eliglustat does not induce clinically significant cardiac events when administered according to pharmacogenomic guidelines. The misinformation regarding Eliglustat's cardiotoxicity, largely driven by speculative interpretations rather than clinical data, is effectively countered by our findings, which show no significant QT prolongation or arrhythmias over a median treatment duration of 8 years.

Inborn metabolic diseases (IMD) are rare conditions that can be diagnosed during adulthood. Patients with IMD may have joint symptoms and the challenge is to establish an early diagnosis in order to institute appropriate treatment and prevent irreversible damage. This review describes the joint manifestations of IMD that may be encountered in adults. The clinical settings considered were arthralgia and joint stiffness as well as arthritis. Unspecific arthralgias are often the first symptoms of hereditary hemochromatosis, chronic low back pain may reveal an intervertebral disc calcification in relation with alkaptonuria, and progressive joint stiffness may correspond to a mucopolysaccharidosis or mucolipidosis. Gaucher disease is initially revealed by painful acute attacks mimicking joint pain described as "bone crises". Some IMD may induce microcrystalline arthropathy. Beyond classical gout, there are also gouts in connection with purine metabolism disorders known as "enzymopathic gouts". Pyrophosphate arthropathy can also be part of the clinical spectrum of Gitelman syndrome or hypophosphatasia. Oxalate crystals arthritis can reveal a primary hyperoxaluria. Destructive arthritis may be indicative of Wilson's disease. Non-destructive arthritis may be seen in mevalonate kinase deficiency and familial hypercholesterolemia.

Arterial calcification is a common phenomenon in the elderly, in patients with atherosclerosis or renal failure and in diabetes. However, when present in very young individuals, it is likely to be associated with an underlying hereditary disorder of arterial calcification. Here, we present an overview of the few monogenic disorders presenting with early-onset cardiovascular calcification. These disorders can be classified according to the function of the respective disease gene into (1) disorders caused by an altered purine and phosphate/pyrophosphate metabolism, (2) interferonopathies, and (3) Gaucher disease. The finding of arterial calcification in early life should alert the clinician and prompt further genetic work-up to define the underlying genetic defect, to establish the correct diagnosis, and to enable appropriate therapy.

We give an update on the etiology and potential treatment options of rare inherited monogenic disorders associated with arterial calcification and calcific cardiac valve disease. Genetic studies of rare inherited syndromes have identified key regulators of ectopic calcification. Based on the pathogenic principles causing the diseases, these can be classified into three groups: (1) disorders of an increased extracellular inorganic phosphate/inorganic pyrophosphate ratio (generalized arterial calcification of infancy, pseudoxanthoma elasticum, arterial calcification and distal joint calcification, progeria, idiopathic basal ganglia calcification, and hyperphosphatemic familial tumoral calcinosis; (2) interferonopathies (Singleton-Merten syndrome); and (3) others, including Keutel syndrome and Gaucher disease type IIIC. Although some of the identified causative mechanisms are not easy to target for treatment, it has become clear that a disturbed serum phosphate/pyrophosphate ratio is a major force triggering arterial and cardiac valve calcification. Further studies will focus on targeting the phosphate/pyrophosphate ratio to effectively prevent and treat these calcific disease phenotypes.