False Positive Diagnosis of Lysosomal Storage Disease Based on Dried Blood Spot Sample; Leucocyte Number of a Challenging Factor

Aim:Recently dried blood spot (DBS) samples have been recommended as a screening test for Lysosomal Storage diseases. Although DBS samples have many advantages including non-invasiveness, cost and transportation, usage of these samples is limited by its high false positive rate. We aimed to investigate any possible effect of the leucocyte number on enzyme activity in dried blood samples in a retrospective study.Materials and Methods:Data was collected from subjects (n=263) for whom hematological parameters were available in the database of Ege University Hospital. The lysosomal enzyme activity results (alpha glycosidase, glycocerebrosidase, alpha galactosidase, sphingomyelinase and galactocerebrosidase) were re-evaluated with regard to the leucocyte number. Enzyme activities were measured using fluorometric and liquid chromatography-tandem mass spectrometry methods.Results:All enzyme activities closely correlated with the total number of leucocyte, since leucocytes are the main source of lysosomal enzymes. Glycocerebrosidase and galactocerebrosidase presented a positive correlation with the number of neutrophils and sphingomyelinase showed a positive correlation with the number of lymphocytes. When we recalculated the lysosomal enzyme activities with regard to the leucocyte number, the false positive rates for glycocerebrosidase, sphingomyelinase and alpha galactosidase decreased from 20%, 10.5% and 10.8% to 4.5%, 4.4% and 4.2%, respectively.Conclusions:Our data indicated that the enzyme activity in dried blood samples including low leucocyte number might be found lower than reference intervals resulting in false positive diagnosis. We concluded that the calculation of enzyme activity with regard to the number of leucocytes might produce more reliable results and might be helpful in decreasing the false positive rate

Case Report A Patient with MSUD: Acute Management with Sodium Phenylacetate/Sodium Benzoate and Sodium Phenylbutyrate

In treatment of metabolic imbalances caused by maple syrup urine disease (MSUD), peritoneal dialysis, and hemofiltration, pharmacological treatments for elimination of toxic metabolites can be used in addition to basic dietary modifications. Therapy with sodium phenylacetate/benzoate or sodium phenylbutyrate (NaPB) in urea-cycle disorder cases has been associated with a reduction in branched-chain amino acid (BCAA) concentrations when the patients are on adequate dietary protein intake. Moreover, NaPB in treatment of MSUD patients is also associated with reduction of BCAA levels in a limited number of cases. However, there are not enough studies in the literature about application and efficacy of this treatment. Our case report sets an example of an alternative treatment's efficacy when extracorporeal procedures are not available due to technical difficulties during attack period of the disease

Clinical Features of 29 Patients with Hereditary Tyrosinemia I in Western Turkey

Aim:The aim of this study was to investigate the long-term outcome of hereditary tyrosinemia Type I (HTI) patients treated with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) to increase knowledge about the clinical outcome in these patients. We want to mention that the patients with HTI have heterogeneous clinic. Early diagnosis and early treatment important to prevent the complications.Materials and Methods:Aretrospective study was carried out with twenty nine patients with HTI and who had been followed up by Ege University Faculty of Medicine, Department of Pediatric Metabolic Diseases and Nutrition Unit between December 1996 and September 2017.Results:Eight patients were acute form, thirteen were subacute and eight patients were chronic form. Mean age onset of clinical symptoms was 3.7±1.6, 9±1.6 and 41±27 months in acute, subacute and chronic HTI patients, respectively. The mean interval from the first symptom the diagnosis was 12.2 months. Mean of follow-up was 82.2 months (minimum: 1 month-maximum: 203 months). Five patients of HTI diagnosed with hepatocellular carcinoma and neurogenic crises were detected in four patients.Conclusion:NTBC treatment is effective and improves the prognosis of HTI. But early diagnosis and treatment leads to much better outcome. Adherence to the diet and treatment and follow-up schedule of the patients are vital

Impact of the COVID-19 Pandemic on Inherited Metabolic Diseases: Evaluation of Enzyme Replacement Treatment Adherence with Telemedicine

Aim:During the coronavirus disease-2019 (COVID-19) pandemic, visiting the hospital and getting regular infusions can be difficult for patients with chronic illnesses. Telemedicine may offer a good option for the management of chronic diseases such as lysosomal storage diseases (LSD).Materials and Methods:LSD patients at the Unit of Metabolic Diseases of Ege University were contacted by phone between April, 2020 and March, 2021 during the COVID-19 pandemic. Telemedicine appointments were performed at intervals every month or three months, depending on the patients’ compliance with their treatment.Results:Ninety-two LSD patients [Mucopolysaccharidosis (MPS) I, MPS II, MPS IVA, MPS VI, MPS VII, Gaucher, Fabry, and Pompe] were included in this study. The total skipped treatment rate within one year was 17.1%. Most of the months of interruption were consonant with the time of social isolation. The treatment interruption in patients under 18 years was lower than in patients over 18 years. A positive correlation was detected between the age of patients and the interruption of treatment.Conclusion:The curfew periods might be one of the causes of missed treatment sessions. Telemedicine is a good method to improve the continuity of treatment. This study showed that the number of interrupted enzyme replacement treatments could be decreased via ongoing telemedicine appointments

Clinical, Biochemical and Molecular Characteristics of Fifteen Patients with Mucopolysaccharidosis Type II in Western Turkey

Aim:Mucopolysaccharidosis Type II (MPS II, Hunter syndrome, OMIM 309900) is a rare X-linked lysosomal storage disease due to a deficiency of the iduronate-2-sulfatase (IDS) enzyme, which is one of the degradative enzymes of mucopolysaccharides. The purpose of this study is to present the clinical, biochemical and molecular characteristics of fifteen patients with MPS II in western Turkey.Materials and Methods:A retrospective study was carried out on fifteen patients with MPS II who were followed up by Ege University Faculty of Medicine, Unit of Pediatric Metabolic Diseases and Nutrition between October 2004 and September 2017.Results:The age range of the patients enrolled in the study was between 11 months and 318 months at the time of diagnosis. The most common symptom was coarse face. On physical examination, all of the patients presented with coarse face, macrocephaly and organomegaly. Except for one patient, all other were severe phenotype. IDS activity was significantly decreased in all patients in whom enzyme analysis was performed. In this study, one novel mutation was described.Conclusion:This is the first study on the clinical and molecular characterization of Turkish MPS II patients. The majority of the patients had neurologic involvement with different degrees of severity. The molecular analysis revealed one novel mutation

Tyrosinemia Type I and Reversible Neurogenic Crisis After a One-Month Interruption of Nitisinone

Hereditary tyrosinemia Type I (HTI) is an autosomal recessive disorder due to a deficiency of the enzyme fumarylacetoacetate hydrolase. The liver is the primary organ that is affected and comorbidities with renal and neurologic systems and hepatocellular carcinoma can be seen as a long-term complication. An effective treatment has been available with 2-[2-nitro-4-trifluoromethylbenzoyl]-1,3-cyclohexanedione (NTBC) since 1992. Neurogenic crises do not take place in HTI patients who are treated with NTBC. Here, we report on a seven-year-old boy who underwent a severe neurological crisis including anorexia, vomiting, weakness, hyponatremia, paresthesia and paralysis of the extremities, seizure and arterial hypertension after an interruption of NTBC treatment. With the re-introduction of NTBC, the patient gradually reacquired normal neurological functions, normal blood pressure and recovered completely

Clinical, Neuroimaging, and Genetic Features of the Patients with L-2-Hydroxyglutaric Aciduria

Aim:L-2-hydroxyglutaric aciduria (L2HGA) is a rare autosomal recessive encephalopathy caused by mutations in the L-2-hydroxyglutarate dehydrogenase gene.Materials and Methods:Here we discuss the clinical and molecular characteristics in patients with L2HGA.Results:There were eight patients with L2HGA. Their median age was 16 (9.5-37) years. Five of them were female and three of them were male. The main symptoms of the patients were psychomotor retardation (8/8), cerebellar ataxia (5/8), extrapyramidal symptoms (7/8) and seizures (4/8). All patients had behavioral problems. Elevated urinary L-2-hydroxy (L-2-OH) glutaric acid was detected and the median level of urine L-2-OH glutaric acid at diagnosis was 146 (60-1460 nmol/mol creat). Characteristic magnetic resonance imaging findings including subcortical cerebral white matter abnormalities with T2 hyperintensities of the dentate nucleus, globus pallidus and putamen were detected. Two patients had homozygous R335X, two patients had homozygous R282Q, two patients had homozygous R302L and one patient had compound heterozygous P302L/A64T mutation in L-2-hydroxyglutarate dehydrogenase (L2HGDH) gene.Conclusion:Because of the slow progression of the disease, the diagnosis of the patients is usually belated. L2HGA must be considered in the differential diagnosis based on clinical findings and specific findings in cranial magnetic resonance imaging. In our study, one of our patients has a novel mutation

Glutaric Aciduria Type I Diagnosis Case with Normal Glutaryl Carnitine and Urine Organic Acid Analysis

Glutaric aciduria Type I (GA-I) is a rare inherited metabolic disease, deficiency of glutaryl-CoA dehydrogenase results in accumulation of the putatively neurotoxic metabolites glutaric and 3-hydroxyglutaric acid (GA, 3-OH-GA) in body tissues, particularly within the brain. Here we presented a 3-year-old girl with hypotonia and dystonia diagnosed with GA-I although the repeated analysis of the carnitine profile and organic acid analyses were normal. The patient has motor, mental retardation, hypotonia. Her weight standard deviation score (SDS) was -1.86 SDS, height SDS was -0.55 SDS, head circumference SDS was -1.01. The physical examination was normal except severe hypotonia. Spot blood carnitine profile, blood amino acid, urine organic acid, lactic acid and pyruvic acid were normal in repeated analysis. Dystonia and spastic tetraparesis developed on her follow-up. Cranial magnetic resonance imaging revealed bilateral cortical atrophy and bilateral striatal and caudate nucleus T2 flair hyperintensities. In GCDH gene analysis p.Y123C (c.368A>G)/p.L340F (c.368A>G) mutation was found. There was no history of encephalopathy. The patient treated with levodopa and trihexyphenidyl and lysine-restricted diet. In the presence of bilateral striatal involvement and cortical atrophy and dystonia, GA-I should be kept in mind. Blood carnitine profile and urine organic acid analyses may not be consistent. It is important to evaluate the cases for genetic investigation