Papers by Cristiano Rizzo
Journal of Inherited Metabolic Disease, 2006
3-Methylglutaconic aciduria is the biochemical marker of several inherited metabolic diseases. Fo... more 3-Methylglutaconic aciduria is the biochemical marker of several inherited metabolic diseases. Four types of 3-methylglutaconic aciduria can be distinguished. In the type I form, accumulation of 3-methylglutaconate is due to deficient activity of 3-methylglutaconyl-CoA hydratase, an enzyme of the leucine degradation pathway. In the other forms, 3-methylglutaconic acid is not derived from leucine but is of unidentified origin, possibly derived from other metabolic pathways, such as mevalonate metabolism. We report five patients, all presenting a severe early-onset phenotype characterized by 3-methylglutaconic aciduria, hypertrophic cardiomyopathy, cataract, hypotonia/developmental delay, lactic acidosis, and normal 3-methylglutaconyl-CoA hydratase activity. This peculiar phenotype, for which a primary mitochondrial disorder is hypothesized, identifies a novel subtype of 3-methylglutaconic aciduria.
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International Journal of Environmental Research and Public Health
Methylmalonic Acidurias (MMAs) are a group of inborn errors of metabolism (IEMs), specifically of... more Methylmalonic Acidurias (MMAs) are a group of inborn errors of metabolism (IEMs), specifically of propionate catabolism characterized by gastrointestinal and neurometabolic manifestations resulting from a deficiency in the function of methylmalonyl-CoA mutase, methylmalonyl-CoA epimerase, and cobalamin metabolism. In Expanded Newborn Screening (NBS), increased levels of propionylcarnitine (C3) and/or of its ratios by MS/MS analysis of dried blood spots (DBS) samples are suggestive for either Propionic Acidemia or MMAs. C3 elevation is not considered a specific marker for these disorders, resulting in high false-positive rates. The use of analyte ratios improves specificity, but it still cannot resolve the diagnostic issue. Second-tier testing are strongly recommended as confirmation of primary NBS results and for a differential diagnosis. LC-MS/MS analysis allows the quantification of more specific markers of the disorder. Here, we report the case of a newborn with a suspected MMA a...
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Orphanet Journal of Rare Diseases
Background Oligosaccharidoses are storage disorders due to enzymatic defects involved in the brea... more Background Oligosaccharidoses are storage disorders due to enzymatic defects involved in the breakdown of the oligosaccharidic component of glycosylated proteins. The defect cause the accumulation of oligosaccharides (OS) and, depending on the lacking enzyme, results in characteristic profiles which are helpful for the diagnosis. We developed a new tandem mass spectrometry method for the screening of urinary OS which was applied to identify a large panel of storage disorders. Methods The method was set-up in urine and dried urine spots (DUS). Samples were analysed, without derivatization and using maltoheptaose as internal standard, by UHPLC-MS/MS with MRM acquisition of target OS transitions, including Glc4, the biomarker of Pompe disease. The chromatographic run was
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Journal of Inherited Metabolic Disease
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American Journal of Medical Genetics Part A
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Revista de Neurología
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PLOS ONE
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Clinica Chimica Acta
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European journal of neurology, Jan 8, 2018
The therapeutic scenario of X-linked adrenoleukodystrophy (X-ALD) is rapidly changing. Whereas th... more The therapeutic scenario of X-linked adrenoleukodystrophy (X-ALD) is rapidly changing. Whereas the disease is well characterized in males, the condition remains to be fully clarified in women carrying ABCD1 variants. Specifically, data on clinical progression are needed, in order to recommend any appropriate management. Objective of this study is to outline the natural history of a cohort of untreated ABCD1 heterozygous female carries. Longitudinal data from a single-center population of 60 carriers were retrospectively reviewed. Demographics, anthropometrics, serum very-long chain fatty acids (VLCFA) levels, clinical parameters and the Adult ALD Clinical Score (AACS) were collected from every recorded visits in a 7 years long period and analyzed to define the phenotype modifications, to determine factors associated with clinical features, to estimate the annual progression rate and the subsequent sample size for interventional trials. 32 patients were eligible for the study, 59.4% ...
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Clinica chimica acta; international journal of clinical chemistry, 2017
The urea cycle disorder carbamoyl phosphate synthetase I deficiency is an important differential ... more The urea cycle disorder carbamoyl phosphate synthetase I deficiency is an important differential diagnosis in the encephalopathic neonate. This intoxication type inborn error of metabolism often leads to neonatal death or severe and irreversible damage of the central nervous system, even despite appropriate treatment. Timely diagnosis is crucial, but can be difficult on routine metabolite level. Here, we report ten neonates from eight families (finally) diagnosed with CPS1 deficiency at three tertiary metabolic centres. In seven of them the laboratory findings were dominated by significantly elevated urinary 3-methylglutaconic acid levels which complicated the diagnostic process. Our findings are both important for the differential diagnosis of patients with urea cycle disorders and also broaden the differential diagnosis of hyperammonemia associated with 3-methylglutaconic aciduria, which was earlier only reported in TMEM70 and SERAC1 defect.
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Journal of inherited metabolic disease, Sep 1, 2016
Transient infantile hypertriglyceridemia (HTGT1; OMIM #614480) is a rare autosomal recessive diso... more Transient infantile hypertriglyceridemia (HTGT1; OMIM #614480) is a rare autosomal recessive disorder, which manifests in early infancy with transient hypertriglyceridemia, hepatomegaly, elevated liver enzymes, persistent fatty liver and hepatic fibrosis. This rare clinical entity is caused by inactivating mutations in the GPD1 gene, which encodes the cytosolic isoform of glycerol-3-phosphate dehydrogenase. Here we report on four patients from three unrelated families of diverse ethnic origins, who presented with hepatomegaly, liver steatosis, hypertriglyceridemia, with or without fasting ketotic hypoglycemia. Whole exome sequencing revealed the affected individuals to harbor deleterious biallelic mutations in the GPD1 gene, including the previously undescribed c.806G > A (p.Arg269Gln) and c.640T > C (p.Cys214Arg) mutations. The clinical features in three of our patients showed several differences compared to the original reports. One subject presented with recurrent episodes ...
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Clinica Chimica Acta, 2016
Peroxisomal disorders (PDs) present with wide phenotypic variability. An appropriate diagnosis re... more Peroxisomal disorders (PDs) present with wide phenotypic variability. An appropriate diagnosis requires a complete analysis of peroxisomal metabolites. We developed a multiplex LC-MS/MS method, using atmospheric pressure chemical ionization allowing the simultaneous determination in plasma of very-long-chain fatty acids, phytanic, pristanic, docosahexaenoic acids and di- and tri-hydroxycolestanoic bile acids. Two hundred microliters of plasma extracted with acetonitrile and 200μl extracted with hexane after an acid hydrolysis were combined, evaporated, dissolved in 10μl of methanol and analyzed. The acquisition was in negative-ion mode using multiple reaction monitoring. The method was validated analytically and clinically. Linearity was 0.1-200μmol/l for docosanoic, cis-13-docosenoic, tetracosanoic, cis-15-tetracosenoic and phytanic acids; 0.01-10μmol/l for hexacosanoic acid; 0.02-20μmol/l for di-hydroxycolestanoic, tri-hydroxycolestanoic and pristanic acids; 0.3-300μmol/l for docosahexaenoic acid. Intra-day and inter-day CVs were below 3.88 and 3.98 respectively for all compounds. Samples from patients with known peroxisomal disorders were compared with controls and the method allowed to confirm the diagnosis in all subjects with a 100% sensitivity. The advantage of this multiplex method is to allow in a single chromatographic run the simultaneous determination of a large number of peroxisome biomarkers with a simple preparative phase without derivatization.
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Acta Paediat, 2007
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Journal of Lipid Research, 2016
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Brain : a journal of neurology, Jan 25, 2016
Ethylmalonic encephalopathy is a fatal, rapidly progressive mitochondrial disorder caused by ETHE... more Ethylmalonic encephalopathy is a fatal, rapidly progressive mitochondrial disorder caused by ETHE1 mutations, whose peculiar clinical and biochemical features are due to the toxic accumulation of hydrogen sulphide and of its metabolites, including thiosulphate. In mice with ethylmalonic encephalopathy, liver-targeted adeno-associated virus-mediated ETHE1 gene transfer dramatically improved both clinical course and metabolic abnormalities. Reasoning that the same achievement could be accomplished by liver transplantation, we performed living donor-liver transplantation in an infant with ethylmalonic encephalopathy. Unlike the invariably progressive deterioration of the disease, 8 months after liver transplantation, we observed striking neurological improvement with remarkable achievements in psychomotor development, along with dramatic reversion of biochemical abnormalities. These results clearly indicate that liver transplantation is a viable therapeutic option for ETHE1 disease.
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Investigación clínica
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Revista de neurologia
Glutaric aciduria type I is an autosomal recessive inborn error of metabolism that is due to a de... more Glutaric aciduria type I is an autosomal recessive inborn error of metabolism that is due to a deficiency of the enzyme glutaryl-CoA dehydrogenase, which gives rise to an accumulation of glutaric and 3-hydroxyglutaric acids in biological fluids. Clinical features present as a sudden-onset severe neurological disorder, characterised by extrapyramidal signs (dystonia-dyskinesia), hypotonia, irritability, macrocephaly and degeneration of the basal ganglia; it may also manifest with unspecific symptoms, such as hypotonia and psychomotor retardation. To describe the clinical, biochemical, neuroimaging and molecular aspects in six Venezuelan patients and to highlight the importance of an early diagnosis of glutaric aciduria type I so as to be able to establish early treatment and thus prevent the neurological damage produced by this disease. Two patients were referred because of macrocephaly, hypotonia and psychomotor retardation, and four more following an encephalopathic crisis. In all of them, neuroimaging studies showed delays in myelination, bilateral frontotemporal hypoplasia and symmetric widening of the Sylvian fissures with poor opercularisation. Urinary organic acid analyses showed raised levels of glutaric and 3-hydroxyglutaric acids, and a molecular analysis confirmed the diagnosis. Organic acid analysis should be indicated in all patients who present macrocephaly, hypotonia, psychomotor retardation or an encephalopathic crisis of unknown causation. This study allowed us to determine the behaviour of the disease in Venezuela, since no epidemiological data exist in the country.
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Orphanet journal of rare diseases, Jan 11, 2015
Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare autosomal recessive d... more Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare autosomal recessive disorder of the urea cycle. HHH has a panethnic distribution, with a major prevalence in Canada, Italy and Japan. Acute clinical signs include intermittent episodes of vomiting, confusion or coma and hepatitis-like attacks. Alternatively, patients show a chronic course with aversion for protein rich foods, developmental delay/intellectual disability, myoclonic seizures, ataxia and pyramidal dysfunction. HHH syndrome is caused by impaired ornithine transport across the inner mitochondrial membrane due to mutations in SLC25A15 gene, which encodes for the mitochondrial ornithine carrier ORC1. The diagnosis relies on clinical signs and the peculiar metabolic triad of hyperammonemia, hyperornithinemia, and urinary excretion of homocitrulline. HHH syndrome enters in the differential diagnosis with other inherited or acquired conditions presenting with hyperammonemia. A systematic review of publ...
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Journal of inherited metabolic disease, 2002
We report on a favourable pregnancy in a woman affected by mut- methylmalonic acidaemia. Under vi... more We report on a favourable pregnancy in a woman affected by mut- methylmalonic acidaemia. Under vitamin B12 and carnitine therapy she remained symptom-free throughout pregnancy, labour, delivery and the postpartum period and gave birth to a term, healthy female newborn. At follow-up, the child shows normal somatic and neurocognitive development.
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JPEN. Journal of parenteral and enteral nutrition, Aug 15, 2015
Thiamine is a water-soluble vitamin implicated in several metabolic processes. Its deficiency, du... more Thiamine is a water-soluble vitamin implicated in several metabolic processes. Its deficiency, due to prolonged parenteral nutrition without adequate vitamin supplementation, can lead to multiorgan failure characterized by cardiovascular impairment and metabolic acidosis refractory to bicarbonate administration. Only thiamine administration allows the remission of symptoms. We report 2 preterm infants with acute thiamine deficiency due to prolonged parenteral nutrition without adequate vitamin supplementation.
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Papers by Cristiano Rizzo