Serum very long-chain fatty acids (VLCFA) levels as predictive biomarkers of diseases severity and probability of survival in peroxisomal disorders.

CONCLUSION: VLCFA levels correlate with the severity of the clinical course of ZS, DBP and mild ZSD. The best predictive value for estimating the projected disease severity and survival time is a concentration of C26:0.

Neonatal cholestasis due to citrin deficiency: diagnostic pitfalls.

Citrin deficiency can manifest in newborns or infants as neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). The paper presents a case of Polish NICCD patient presenting with low birth weight, failure to thrive, prolonged cholestatic jaundice with coagulopathy and hypoalbuminemia with normal results of MS/MS newborn screening but with high blood citrulline level observed at 3 months of age. Unreported findings included N-hypoglycosylation and increased serum very-long-chain fatty acids (VLCFA), probably secondary to liver impairment. Final diagnosis was established based on whole-exome sequencing (WES) analysis.

Mild Zellweger syndrome due to functionally confirmed novel PEX1 variants.

Zellweger spectrum disorders (ZSD) constitute a group of rare autosomal recessive disorders characterized by a defect in peroxisome biogenesis due to mutations in one of 13 PEX genes. The broad clinical heterogeneity especially in late-onset presenting patients and a mild phenotype complicates and delays the diagnostic process. Here, we report a case of mild ZSD, due to novel PEX1 variants. The patient presented with an early hearing loss, bilateral cataracts, and leukodystrophy on magnetic resonance (MR) images. Normal results of serum very-long-chain fatty acids (VLCFA) and phytanic acid were found. Molecular diagnostics were performed to uncover the etiology of the clinical phenotype. Using whole exome sequencing, there have been found two variants in the PEX1 gene-c.3450T>A (p.Cys1150*) and c.1769T>C (p.Leu590Pro). VLCFA measurement in skin fibroblasts and C26:0-lysoPC in dried blood spot therefore was performed. Both results were in line with the diagnosis of ZSD. To conclude, normal results of routine serum VLCFA and branched-chain fatty acid measurement do not exclude mild forms of ZSD. The investigation of C26:0-lysoPC should be included in the diagnostic work-up in patients with cataract, hearing loss, and leukodystrophy on MR images suspected to suffer from ZSD.

[Transaldolase deficiency - clinical outcome, pathogenesis, diagnostic process].

Transaldolase deficiency is a rare inborn autosomal recessive error of the pentose phosphate pathway that, to date, has been diagnosed in 33 patients, including 4 from Poland. The aim of this manuscript was to present the clinical presentation, pathogenesis and diagnostic process of transaldolase deficiency. The authors also present a diagnostic algorithm of transaldolase deficiency.

Dominant ELOVL1 mutation causes neurological disorder with ichthyotic keratoderma, spasticity, hypomyelination and dysmorphic features.

BACKGROUND: Ichthyosis and neurological involvement occur in relatively few known Mendelian disorders caused by mutations in genes relevant both for epidermis and neural function. OBJECTIVES: To identify the cause of a similar phenotype of ichthyotic keratoderma, spasticity, mild hypomyelination (on MRI) and dysmorphic features (IKSHD) observed in two unrelated paediatric probands without family history of disease. METHODS: Whole exome sequencing was performed in both patients. The functional effect of prioritised variant in ELOVL1 (very-long-chain fatty acids (VLCFAs) elongase) was analysed by VLCFA profiling by gas chromatography-mass spectrometry in stably transfected HEK2932 cells and in cultured patient's fibroblasts. RESULTS: Probands shared novel heterozygous ELOVL1 p.Ser165Phe mutation (de novo in one family, while in the other family, father could not be tested). In transfected cells p.Ser165Phe: (1) reduced levels of FAs C24:0-C28:0 and C26:1 with the most pronounced effect for C26:0 (P=7.8×10-6 vs HEK293 cells with wild type (wt) construct, no difference vs naïve HEK293) and (2) increased levels of C20:0 and C22:0 (P=6.3×10-7, P=1.2×10-5, for C20:0 and C22:0, respectively, comparison vs HEK293 cells with wt construct; P=2.2×10-7, P=1.9×10-4, respectively, comparison vs naïve HEK293). In skin fibroblasts, there was decrease of C26:1 (P=0.014), C28:0 (P=0.001) and increase of C20:0 (P=0.033) in the patient versus controls. There was a strong correlation (r=0.92, P=0.008) between the FAs profile of patient's fibroblasts and that of p.Ser165Phe transfected HEK293 cells. Serum levels of C20:0-C26:0 FAs were normal, but the C24:0/C22:0 ratio was decreased. CONCLUSION: The ELOVL1 p.Ser165Phe mutation is a likely cause of IKSHD.

Long-Term Systematic Monitoring of Four Polish Transaldolase Deficient Patients.

INTRODUCTION: Transaldolase deficiency (TALDO; OMIM 606003) is a rare inborn autosomal recessive error of the pentose phosphate pathway that, to date, has been diagnosed in 33 patients. Tzhere are few reports regarding the long-term follow-up of these patients.The aim of our study is to present the disease progression in the form of a systematic long-term follow-up of four Polish patients with TALDO. METHODS AND RESULTS: We report four patients who manifested early onset TALDO. They were monitored with systematic clinical and laboratory examinations for 4-13 years. The dominant feature was an early liver injury, with subsequent renal tubulopathy. All patients presented with osteopenia and poor physical development. Our data shows that polyol concentrations seem to decrease with age. CONCLUSIONS: In our patients, a progressive coagulopathy was the most sensitive parameter of liver dysfunction. Nodular fibrosis of the liver developed over the natural course of TALDO. This is the first report of long-term systematic clinical and biochemical monitoring of the disease progress in patients with TALDO.

Mild Zellweger syndrome due to a novel PEX6 mutation: correlation between clinical phenotype and in silico prediction of variant pathogenicity.

Zellweger syndrome (ZS) is a consequence of a peroxisome biogenesis disorder (PBD) caused by the presence of a pathogenic mutation in one of the 13 genes from the PEX family. ZS is a severe multisystem condition characterized by neonatal appearance of symptoms and a shorter life. Here, we report a case of ZS with a mild phenotype, due to a novel PEX6 gene mutation. The patient presented subtle craniofacial dysmorphic features and slightly slower psychomotor development. At the age of 2 years, he was diagnosed with adrenal insufficiency, hypoacusis, and general deterioration. Magnetic resonance imaging showed a symmetrical hyperintense signal in the frontal and parietal white matter. Biochemical tests showed elevated liver transaminases, elevated serum very long chain fatty acids, and phytanic acid. After the death of the child at the age of 6 years, molecular diagnostics were continued in order to provide genetic counseling for his parents. Next generation sequencing (NGS) analysis with the TruSight One™ Sequencing Panel revealed a novel homozygous PEX6 p.Ala94Pro mutation. In silico prediction of variant severity suggested its possible benign effect. To conclude, in the milder phenotypes, adrenal insufficiency, hypoacusis, and leukodystrophy together seem to be pathognomonic for ZS.

The Role of MR Imaging in the Assessment of Clinical Outcomes in Children with X-Linked Adrenoleukodystrophy after Allogeneic Haematopoietic Stem Cell Transplantation.

BACKGROUND: The aim of the study was to analyse MR images of the brain, including advanced MR techniques, such as single voxel spectroscopy (MRS) and diffusion tensor imaging (DTI), in children with X-linked adrenoleukodystrophy (X-ALD) before and after haematopoietic stem cell transplantation (HSCT) and to establish the imaging criteria which may be helpful in the assessment of disease staging, qualification to HSCT and follow-up. MATERIAL/METHODS: Seven boys, aged 5-10 years, (mean 8.14 years) with biochemically proved X-ALD, underwent plain MR imaging with a 1.5 T unit before and after HSCT. Structural images were analyzed using an MRI severity scale (Loes scale). In one patient the follow-up examinations included MRS with the assessment of metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr), as well as DTI with evaluation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in several white matter tracts. RESULTS: Two boys had an MRI severity score before HSCT equal to <8 points, and after HSCT they showed no clinical or radiological progression. In 5 patients with a higher severity score (from 8 to 16 points, mean 10.9) before HSCT, clinical and radiological progression was observed (MRI severity score from 17 to 25 points, mean 20.9). Follow-up advanced MRI techniques in one boy showed metabolic alterations, as well as decreased FA and ADC values in all evaluated areas. CONCLUSIONS: Children at an early stage of X-ALD (below 8 points in MRI severity scale) are more likely to benefit from HSCT. DTI and MRS seem to be more useful imaging methods to assess the progression of X-ALD.

Monitoring of very long-chain fatty acids levels in X-linked adrenoleukodystrophy, treated with haematopoietic stem cell transplantation and Lorenzo's Oil.

X-linked adrenoleukodystrophy is a rare, neurodegenerative peroxisomal disorder connected with mutation in the ABCD1 gene, causing impairment of the peroxisomal ß-oxidation process and in consequence, accumulation of very long-chain fatty acids (VLCFA) in blood and tissues. In this study we present serum very long-chain fatty acids levels during clinical course in an X-linked adrenoleukodystrophy patient after haematopoietic stem cell transplantation (HSCT) and on Lorenzo's Oil in a 11 years' period. The patient was diagnosed at the age of 8 months by family screening. The administration of LO was started at 2 years of age. HSCT from a family donor was performed twice. VLCFA serum levels were detected by the GC method. Chimaerism subsequent to HSCT was also analyzed. Increasing very long-chain fatty acids levels correlate with a decreasing chimaerism level after haematopoietic stem cell transplantation. The sequential monitoring of very long-chain fatty acids serum levels is important and useful for assessment of engraftment, graft failure or rejection.

Clinical and molecular characteristics of two transaldolase-deficient patients.

UNLABELLED: Transaldolase (TALDO) deficiency is a rare metabolic disease in the pentose phosphate pathway, which manifests as a severe, early-onset multisystem disease. The body fluids of affected patients contain increased polyol concentrations and seven-carbon chain carbohydrates. We report the molecular and clinical findings in two recently diagnosed transaldolase-deficient children, both presented at birth. During infancy, they presented thin skin with a network of visible vessels, spider telangiectasias and multiple haemangiomas. Such unusual skin changes are characteristic of liver damage. Later, the patients developed rapidly progressive nodular liver fibrosis, tubulopathy and severe clotting disturbances. The clinical features of these patients were in line with previously studied patients with transaldolase deficiency. The diagnosis was established by detecting high concentrations of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7-phosphate in the urine. Detection was made by gas chromatography and liquid chromatography-tandem mass spectrometry and then confirmed by molecular analysis of the TALDO gene. CONCLUSION: Transaldolase deficiency, a rare early-onset multisystem disease, should be considered by neonatologists, paediatricians, hepatologists and nephrologists in the differential diagnosis of patients presenting hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure and tubulopathy.

[A newly discovered metabolic diseases due to defects in the pentose pathway]. / Nowo opisane choroby metaboliczne zwiazane z bledami metabolizmu na szlaku przemiany pentoz.

Two previously unreported inborn errors of metabolism occur in the reversible part of the pentose phosphate pathway. Deficiency of ribose-5-phosphate isomerase has been described in one patient who suffered from a progressive leukoencephalopathy and developmental delay. Transaldolase deficiency has been diagnosed in 11 patients from 6 families in which the probands presented in the newborn and antenatal period with hepatospIenomegaly, hemolytic anaemia, hepatic fibrosis, kidney problems. Enzymes deficiency results in accumulations in body fluids erythritol, arabitol, ribitol, sedoheptitol, sedoheptulose, sedoheptulose-7-phosphate. Isomerase and transaldolase activity can be determined in leukocytes or fibroblasts.

[Peroxisomes--functions and disturbances in human metabolism]. / Peroksysomy--funkcje i zaburzenia metaboliczne.

Peroxisomes, classical compartments of eucaryotic cells have significant functions in cellular metabolism, which beta-oxidation fatty acids and detoxification of H2O2 are the most important biochemical process. Defects in genes encoding for peroxisomal proteins result in biochemical malfunctioning of these organelles and constitute base for severe human's inherited diseases. This article presents the most important aspects concerning peroxisomal biogenesis, biochemical functions and their disturbance.

Determination of urinary D-/L-arabinitol ratios as a biomarker for invasive candidiasis in children with cardiac diseases.

A non-invasive, non-culture-based method of determining urinary D-/L-arabinitol (D-/L-ARA) ratios was investigated as a tool for the diagnosis of invasive candidiasis in nosocomial paediatric infection cases. The study encompassed 138 children aged 4 days to 16 years (mean ± SD=1.6 ± 4.2 years) with congenital heart defects (91.4%) or with rhythm disorders or circulatory failure (8.6%). ARA enantiomers were detected by GC using an electron capture detector. Positive D-/L-ARA ratios were found for 11/11 patients with proven candidiasis and 17/19 patients with clinically suspected invasive candidiasis. Thirty children were undergoing antifungal chemotherapy. D-/L-ARA ratios (mean ± SD) were 2.601 ± 0.544 in hospitalized cardiac patients without fungal infection and 5.120 ± 1.253 in those receiving antifungal therapy (P<0.001). The sensitivity of the method was 100%, the specificity 97.2%, the positive predictive value was 78.6% and the negative predictive value was 100%.

Transaldolase deficiency in two new patients with a relative mild phenotype.

Transaldolase (TALDO) deficiency is a recently described inborn error of metabolism of the pentose phosphate pathway that so far has been diagnosed in only eight patients. In this article, we report the clinical course and biochemical findings of two newly identified patients with TALDO deficiency-two sons of consanguineous parents from Polish origin, presenting with neonatal onset of bleeding diathesis, haemolytic anemia, thrombocytopenia and hepatosplenomegaly. Subsequently the patients had persistent thrombocytopenia, a bleeding tendency, impaired liver function and fibrosis. Their physical and psychomotor development progressed normally.

Serum very-long-chain fatty acids levels determined by gas chromatography in the diagnosis of peroxisomal disorders in Poland.

Peroxisomal disorders are a large group of genetically determined metabolic diseases in which the biogenesis of peroxisomes is defective or there is a deficiency of only a single enzyme activity or substrate transporter. The objective of this report is to present ten years of experience in the diagnostics of peroxisomal disorders in Poland. Very-long-chain fatty acid (VLCFA) levels as a biomarker for peroxisomal defects were determined by gas chromatography in 1264 subjects with suspicion of peroxisome disease. Peroxisome biogenesis disorders (PBD) were diagnosed in 8 patients, bifunctional protein deficiency in 3 and X-linked adrenoleukodystrophy (X-ALD/AMN) in 127 hemi- or heterozygotes. The frequency of PBD was estimated as 0.20 : 100 000, and that of X-ALD/AMN 2.9 : 100,000 in Poland. Mean total delay time (onset of symptoms and diagnosis) for X-ALD/AMN was 2.2 years (range 0.25-13). High correlation of serum C26:0 concentration and survival for PBD patient (r2 = 0.822; p < 0.001) was found.

Clinical and neuropathological picture of familial encephalopathy with bifunctional protein deficiency.

Peroxisomal diseases are a heterogeneous group of genetic metabolic disorders which are caused by incorrect biogenesis of peroxisomes or a defect in activity of particular enzymes located in those organelles.D-bifunctional protein (D-BP) deficiency belongs to the second group of peroxisomal diseases characterised by dysfunction of a single peroxisomal enzyme. Bifunctional protein is a catalyst in the second and third stage of the beta-oxidation of fatty acids. Gene locus of bifunctional protein deficiency comprises chromosomes 5q2 and 3p23-p22. The authors present two siblings with progressing family encephalopathy. In the younger brother the diagnosis of a bifunctional protein deficiency was made. The girl died before a diagnosis was made;however, due to the presence of a very similar clinical condition a suspicion arises that the girl had a peroxisomal disease. In the siblings were ascertained characteristic dysmorphic features, delayed psychomotor development, polymorphic epileptic seizures and generalized muscular hypotonia with areflexia. The neuropathological findings were consistent in general with MRI findings showing features of hypomyelination. Also neuron heterotopias that were found in autopsy are a form of pathology typical for D-BP.

Cerebral childhood and adolescent X-linked adrenoleukodystrophy. Clinical presentation, neurophysiological, neuroimaging and biochemical investigations.

Clinical, neurophysiological, neuroimaging and biochemical studies were performed in five boys with childhood and adolescent form of cerebral X-ALD, which is a very rare disease in developmental age. In all patients, rapidly progressive spasticity, ataxia and mental deterioration were found. Seizures occurred in four of them. Additionally, visual and hearing impairment were observed in four and three patients respectively. Adrenal insufficiency was also diagnosed in four cases. MR revealed extensive demyelination located mainly symmetrically in the parieto-occipital areas, in one patient in whom asymmetrical lesions in that region were found. All patients had abnormal visual, brainstem and somatosensory evoked potentials recording, reflecting the central demyelination occurring in X-ALD. The clinical diagnosis in every case was confirmed by the significantly elevated concentration of very long chain fatty acids (VLCFA) measured in plasma in comparison to normal values.

Urinary D-arabinitol/L-arabinitol levels in infants undergoing long-term antibiotic therapy.

Long-term antibiotic therapy is one of the main risk factors for mycosis. The urinary D-arabinitol/L-arabinitol (D-/L-ARA) ratio (a biomarker of several Candida species) was determined by gas chromatography with an electron capture detector in samples from 51 infants undergoing long-term antibiotic therapy. Although 47 of these children had higher D-/L-ARA ratios than healthy controls (P<0.0003), their values nonetheless remained within upper-normal limits (D-/L-ARA ratio of <3.6). Four children with suspected invasive candidiasis had above-normal ratios that normalized with fluconazole treatment.

Gas chromatographic determination of D-/L-arabinitol ratio in healthy Polish children.

The D-/L-arabinitol enantiomers ratio (a marker of disseminated candidiasis of Candida species) in urine was determined by gas chromatography (GC) in 198 healthy Polish children ranging in age from 0 to 18 years. The urine samples were dry and trifluoroacetic anhydride (TFAA)-treated. Enantiomers derivatives were separated on a chiral column (beta-Dex 120, 60 m x 0.25 mm I.D.). A glass "solid-phase" injector and electron capture detector (ECD) were used. The ECD response was linear with correlation coefficients 0.999. The limit of detection was 0.02 micromol/l. Good results in terms of reproducibility, accuracy (RSD<10%, bias<6%), and linearity were obtained from real urine samples containing up to 400 micromol/l D-arabinitol. TFA-arabinitol derivatives in biological samples were stable from 1 to 5 days (depending on the arabinitol contents), while TFA-arabinitol standard derivatives were stable for 2 weeks. The identity of D- and L-arabinitol were confirmed by GC-MS analysis. The mean D-/L-arabinitol ratios ranged from 2.48 to 1.65 in the examined groups. The D-/L-arabinitol ratio was found to be exponentially regressive with age. A few cases of diagnosis of disseminated candidiasis by the GC method and confirmed by blood culture are described. The described GC method was also used for monitoring antifungal treatment of patients with disseminated candidiasis.