In the last two decades, the introduction of tandem mass spectrometry in clinical laboratories has enabled simultaneous testing of numerous acylcarnitines and amino acids from dried blood spots for ...detecting many aminoacidopathies, organic acidurias and fatty acid oxidation disorders. The expanded newborn screening was introduced in Slovenia in September 2018. Seventeen metabolic diseases have been added to the pre-existing screening panel for congenital hypothyroidism and phenylketonuria, and the newborn screening program was substantially reorganized and upgraded.
Tandem mass spectrometry was used for the screening of dried blood spot samples. Next-generation sequencing was introduced for confirmatory testing. Existing heterogeneous hospital information systems were connected to the same laboratory information system to allow barcode identification of samples, creating reports, and providing information necessary for interpreting the results.
In t he first y ear of t he expanded newborn screening a total of 15,064 samples w ere screened. Four patients were confirmed positive with additional testing.
An expanded newborn screening program was successfully implemented with the first patients diagnosed before severe clinical consequences.
Interstitial 3p21.31 deletions have been very rarely reported. We describe a 7-year-old boy with global developmental delay, specific facial characteristics, hydronephrosis, and hypothyreosis with a ...de novo deletion of 3p21.31, encompassing 29 OMIM genes. Despite the wide use of microarrays, no similar case has been reported in the literature so far. Five overlapping cases are deposited in the DECIPHER database, 2 of which have significant overlapping chromosomal aberrations. They both share some phenotypic characteristics with our case, e.g. developmental delay, intellectual disability and facial dysmorphism (arched eyebrows, hypertelorism, low-set ears, and a large nose tip). In addition, loss-of-function mutations in the SETD2 gene (OMIM 612778) of the deleted region have been described in 3 patients, presenting with some similar clinical features, namely overgrowth, intellectual disability, speech delay, hypotonia, autism, and epilepsy. Therefore, SETD2 may explain part of the phenotype in our case. We focused on 3 other genes in the deleted region, based on their known functions, namely CSPG5 (OMIM 606775), PTH1R (OMIM 168468) and SMARCC1 (OMIM 601732), and assessed their potentially important role in describing the patient's phenotype. Additional cases with haploinsufficiency of this region are needed to elucidate further genotype-phenotype correlations.
Phosphoribosylpyrophosphate synthetase 1 (PRSI) is an enzyme involved in nucleotide metabolism. Pathogenic variants in the PRPS1 are rare and PRS-I deficiency can manifest as three clinical ...syndromes: X-linked non-syndromic sensorineural deafness (DFN2), X-linked Charcot-Marie-Tooth neuropathy type 5 (CMTX5) and Arts syndrome. We present a Slovenian patient with PRS-I enzyme deficiency due to a novel pathogenic variant – c.424G > A (p.Val142Ile) in the PRPS1 gene, who presented with gross motor impairment, severe sensorineural deafness, balance issues, ataxia, and frequent respiratory infections. In addition, we report the findings of a systemic literature review of all described male cases of Arts syndrome and CMTX5 as well as intermediate phenotypes. As already proposed by other authors, our results confirm PRS-I deficiency should be viewed as a phenotypic continuum rather than three separate syndromes because there are multiple reports of patients with an intermediary clinical presentation.
BACKGROUND Niemann-Pick disease (NPD) type A is an autosomal recessive lipid storage disorder caused by acid sphingomyelinase deficiency due to a mutation in the SMPD1 gene. Type A is the most severe ...phenotype of NPD, with early onset in infancy and unfavorable outcome in early childhood. CASE REPORT An 11-month-old boy with hepatosplenomegaly, elevated liver transaminases, and faltering growth was admitted to our hospital for further assessment of potential liver disease. He had severe generalized muscular hypotonia, muscular hypotrophy, reduced muscular strenght, joint laxity, weak deep tendon reflexes, and severe motor developmental delay. Leukodystrophy was seen on the brain MRI, and brainstem auditory evoked potentials were characteristic for auditory neuropathy. A chest X-ray showed signs of interstitial lung disease, which was not further evaluated due to absence of respiratory distress. Liver biopsy histopathologic findings were indicative for lipid storage disease. Genetic analysis showed that the patient is a compound heterozygote in the SMPD1 gene - (NM_000543.5): c.573delT p.(Ser192Alafs*65), which was inherited from the mother and c.1267C>T p.(His423Tyr) was inherited from the father. Both variants were previously individually reported in NPD type A and B. The clinical phenotype in our patient was characteristic of NPD type A, with an early onset and a rapidly progresive neurodegeneration. The patient was included in multidisciplinary follow-up, providing him symptomatic treatment and support. CONCLUSIONS We present a case of NPD type A caused by a rare compound heterozygote mutation in the SMPD1 gene. Most clinical findings and the disease course were typical for NPD type A, except for bilateral auditory neuropathy, which seems to be an uncommon finding in this phenotype and could be underestimated due to infrequent testing for auditory dysfunction.
Angiokeratomas are the cutaneous hallmark of Fabry disease. Although it is well established that enzyme replacement therapy (ERT) prevents or slows the progression of disease on target organs in the ...majority of patients, the long-term effect of ERT on angiokeratomas remains unknown. We present a patient diagnosed with Fabry disease at age 11, with rapid progression of new angiokeratomas in typical regions before beginning treatment with ERT. To date, our patient has been treated with ERT for 10 years. During the treatment period, new angiokeratomas have not arisen nor have existing ones enlarged during puberty, adolescence, and early adulthood. Furthermore, partial regression of the angiokeratomas has occurred in association with regression of left ventricular hypertrophy and anhidrosis. Overall, this case suggests that long-term ERT could stop the progression of angiokeratomas and induce their partial regression but does not produce complete resolution. Importantly, regression of angiokeratomas might be a marker of systemic target-organ efficacy of ERT.
Rare diseases (RDs), with distinctive and complex features, pose a serious public health concern and represent a considerable challenge for the Slovenian healthcare system. One of the potential ...approaches to tackling this problem and treating patients with RDs in a quality and effective manner is to form an RD ecosystem. This represents a functional environment that integrates all stakeholders, procedures, and relationships required for the coordinated and effective treatment of patients. This paper explores the current situation in the field of RDs, especially in light of the proposed ecosystemic arrangement, and provides an outline for the design of an RD ecosystem in Slovenia. The research applies a case-study design, where focus groups are used to collect evidence from the field, assess the state of affairs, and generate ideas. Structured focus group discussions were conducted with preeminent experts affiliated with the leading institutions in the field of RDs in Slovenia. Analyses and interpretations of the obtained data were carried out by means of conventional content analysis. Setting up an RD ecosystem in Slovenia would lead to significant benefits for patients, as it could promote the coordination of healthcare treatment and facilitate extensive monitoring of the treatment parameters and outcomes. A well-organized RD ecosystem could garner considerable systemic benefits for evidence-informed policymaking, a better utilization of resources, and technological innovation. Delivering quality healthcare in this complex field is largely reliant on the effective integration and collaboration of all entities within the RD ecosystem, the alignment of related systemic factors, and the direction of healthcare services to support the needs and well-being of patients with RDs.
Phenylketonuria (PKU) was the first disease to be identified by the newborn screening (NBS) program. Currently, there are various methods for determining phenylalanine (Phe) values, with tandem mass ...spectrometry (MS/MS) being the most widely used method worldwide. We aimed to compare the MS/MS method with the fluorometric method (FM) for measuring Phe in the dried blood spot (DBS) and the efficacy of both methods in the NBS program. The FM was performed using a neonatal phenylalanine kit and a VICTOR2
D fluorometer. The MS/MS method was performed using a NeoBase
2 kit and a Waters Xevo TQD mass spectrometer. The Phe values measured with the MS/MS method were compared to those determined by the FM. The cut-off value for the NBS program was set at 120 µmol/L for FM and 85 µmol/L for MS/MS. We analyzed 54,934 DBS. The measured Phe values varied from 12 to 664 µmol/L, with a median of 46 µmol/L for the MS/MS method and from 10 to 710 µmol/L, with a median of 70 µmol/L for the FM. The Bland-Altman analysis indicated a bias of -38.9% (-23.61 µmol/L) with an SD of 21.3% (13.89 µmol/L) when comparing the MS/MS method to the FM. The Phe value exceeded the cut-off in 187 samples measured with FM and 112 samples measured with MS/MS. The FM had 181 false positives, while the MS/MS method had 106 false positives. Our study showed that the MS/MS method gives lower results compared to the FM. Despite that, none of the true positives would be missed, and the number of false-positive results would be significantly lower compared to the FM.
Inborn errors of metabolism (IEM) are disorders with a block in the metabolic pathway caused by a genetic defect of a specific enzyme. Although each of these diseases is quite rare, as a group they ...account for a significant proportion of newborn and childhood morbidity and mortality. Early diagnosis is important to prevent complications or even death of the child. Selective screening is an important diagnostic tool for the diagnosis of IEM.
In Slovenia, symptomatic patients with suspected IEM are referred to the University Children's Hospital Ljubljana. Techniques used for selective screening are gas chromatography-mass spectrometry, ion exchange chromatography-post-column derivatization, liquid chromatography-tandem mass spectrometry and isoelectric focusing. Fluorimetric method is used for enzyme activity measurement.
There are 168 patients with amino and organic acidemias, 5 patients with disorders in fatty acids metabolism, 1 patient with a congenital disorder of glycosylation, 42 patients with Fabry disease (of which 37 are adult) and 20 patients with Gaucher disease (of which 18 are adult) in the Slovenian Register for Rare Diseases.
In Slovenia, management of patients with IEM is centralized at the University Children's Hospital, with the exception of adult patients with Fabry and Gaucher disease. The team work is well organized with close cooperation between the laboratory and pediatricians specialized in metabolic disorders. According to the known frequencies of IEM from the literature, we would expect more positive results than obtained. To evaluate these results, we are planning to perform a pilot study on expanded newborn screening.
This paper aims to report collective information on safety and efficacy of empagliflozin drug repurposing in individuals with glycogen storage disease type Ib (GSD Ib).
This is an international ...retrospective questionnaire study on the safety and efficacy of empagliflozin use for management of neutropenia/neutrophil dysfunction in patients with GSD Ib, conducted among the respective health care providers from 24 countries across the globe.
Clinical data from 112 individuals with GSD Ib were evaluated, representing a total of 94 treatment years. The median age at start of empagliflozin treatment was 10.5 years (range = 0-38 years). Empagliflozin showed positive effects on all neutrophil dysfunction–related symptoms, including oral and urogenital mucosal lesions, recurrent infections, skin abscesses, inflammatory bowel disease, and anemia. Before initiating empagliflozin, most patients with GSD Ib were on G-CSF (94/112; 84%). At the time of the survey, 49 of 89 (55%) patients previously treated with G-CSF had completely stopped G-CSF, and another 15 (17%) were able to reduce the dose. The most common adverse event during empagliflozin treatment was hypoglycemia, occurring in 18% of individuals.
Empagliflozin has a favorable effect on neutropenia/neutrophil dysfunction–related symptoms and safety profile in individuals with GSD Ib.
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