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Anibh M Das

Publications and source records attributed to Anibh M Das.

15 recordsLinked to original sources
PubMed2006

Schimke versus non-Schimke chronic kidney disease: an anthropometric approach.

Schimke-immuno-osseous dysplasia is a rare autosomal-recessive multisystem disorder with the main clinical features of disproportionate growth deficiency, defective cellular immunity, and progressive renal disease. It is caused by mutations of SMARCAL1, a gene encoding a putative chromatin remodeling protein of unknown function. Because a detailed description of the clinical features is an essential first step in elucidating the function of SMARCAL1, we present the first detailed anthropometric data for Schimke-immuno-osseous dysplasia patients. By comprehensive anthropometric examination (28 parameters) of 8 patients (3 females) with the typical findings of Schimke-immuno-osseous dysplasia (mean age: 14.8 years; range: 4.9-30.5 years) and 304 patients (117 females) with congenital and hereditary chronic kidney disease (mean age: 10.7 +/- 4.8 years; range: 3-21.8 years), we show that Schimke-immuno-osseous dysplasia patients differ significantly from those with other forms of chronic kidney disease. z scores were calculated with reference limits derived from 5155 healthy children (2591 females) aged 3 to 18 years. The key finding was that, in the latter group, median leg length was significantly more reduced than sitting height, whereas in Schimke-immuno-osseous dysplasia patients, the reduction of sitting height was significantly more pronounced than for leg length. Therefore, the ratio of sitting height/leg length might be a simple tool for the clinician to distinguish Schimke-immuno-osseous dysplasia from other chronic kidney disease patients. Schimke-immuno-osseous dysplasia is very likely if this ratio is < 0.83. However, other forms of chronic kidney disease have to be discussed in case of a ratio > 1.01.

Adolescent↗
PubMed2006

[Schimke immuno-osseous dysplasia. A pediatric disease reaches adulthood].

BACKGROUND: Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive multisystemic disorder caused by mutations of the SMARCAL 1 gene (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1). CLINICAL FEATURES: Main clinical features are: disproportional growth deficiency due to spondyloepiphyseal dysplasia, nephrotic syndrome with focal and segmental glomerulosclerosis, and defective cellular immunity. Patients with severe SIOD have life-limiting complications like cerebral ischemia due to vaso-occlusive processes. Only a few patients reached adulthood. CASE REPORTS: The clinical course of four adult SIOD patients is presented. CONCLUSION: Even patients with severe SIOD can reach adulthood. Therefore, doctors working in the field of internal medicine and family doctors should be familiar with the clinical picture of SIOD.

Adolescent↗
PubMed2006

Newborn screening for hepatorenal tyrosinemia: Tandem mass spectrometric quantification of succinylacetone.

BACKGROUND: False-positive and false-negative results occur in current newborn-screening programs for hepatorenal tyrosinemia, which measure tyrosine concentrations in blood spots, sometimes in combination with other metabolites, including succinylacetone. We present our experience with a newly described method for succinylacetone quantification in routine newborn screening. METHODS: Succinylacetone was extracted from blood spots that had already been extracted with absolute methanol for acylcarnitine and amino acid analysis. The solvent was acetonitrile-water (80:20 by volume) containing formic acid, hydrazine hydrate, and 100 nmol/L 5,7-dioxooctanoic acid as internal standard. Analysis was performed by tandem mass spectrometry in a separate run. RESULTS: Of 61,344 samples, 99.6% had succinylacetone concentrations < or =5 micromol/L. With a cutoff of 10 micromol/L, no false-positive results were obtained. In 2 patients, the succinylacetone concentrations in the dried blood spots from the 36th and 56th hours of life were 152 and 271 micromol/L, respectively, and the tyrosine concentrations were 54 and 129 micromol/L. Hepatorenal tyrosinemia was subsequently confirmed in both patients. Retrospective analysis of the neonatal screening samples of 2 additional known patients revealed increased succinylacetone concentrations of 46 and 169 micromol/L, respectively. CONCLUSIONS: Tandem mass spectrometric quantification directly from residual blood spots is a useful method for the early detection of hepatorenal tyrosinemia in newborn-screening programs.

Blood Specimen Collection↗
PubMed2006

Isolated mitochondrial long-chain ketoacyl-CoA thiolase deficiency resulting from mutations in the HADHB gene.

BACKGROUND: The human mitochondrial trifunctional protein (MTP) complex is composed of 4 hydroacyl-CoA dehydrogenase-alpha (HADHA) and 4 hydroacyl-CoA dehydrogenase-beta (HADHB) subunits, which catalyze the last 3 steps in the fatty acid beta-oxidation spiral of long-chain fatty acids. The HADHB gene encodes long-chain ketoacyl-CoA thiolase (LCTH) activity, whereas the HADHA gene contains the information for the long-chain enoyl-CoA hydratase and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) functions. At present, 2 different biochemical phenotypes of defects in the mitochondrial trifunctional protein complex are known: isolated LCHAD deficiency and generalized MTP deficiency, with decreased activities of all 3 enzymes. Isolated LCTH deficiency with mutations in the HADHB gene has not been reported. PATIENT AND RESULTS: We report a male newborn who presented with lactic acidosis, pulmonary edema, and cardiomyopathy leading to acute heart failure and death at the age of 6 weeks. Routine newborn screening by tandem mass spectrometry showed increased concentrations of the acylcarnitines tetradecenoylcarnitine, hexadecenoylcarnitine, hydroxypalmitoylcarnitine, and hydroxyoctadecenoylcarnitine, suggesting LCHAD deficiency or complete MTP deficiency. Enzyme investigations revealed very low LCTH (4% of normal) and normal LCHAD activities, whereas molecular analysis showed compound heterozygosity for 185G > A (R62H) and 1292T > C (F431S) mutations in the HADHB gene. CONCLUSION: We describe the first case of isolated LCTH deficiency based on a mutation in the HADHB gene.

Acetyl-CoA C-Acyltransferase↗
PubMed2006

Newborn screening for 3-methylcrotonyl-CoA carboxylase deficiency: population heterogeneity of MCCA and MCCB mutations and impact on risk assessment.

New technology enables expansion of newborn screening (NBS) of inborn errors aimed to prevent adverse outcome. In conditions with a large share of asymptomatic phenotypes, the potential harm created by NBS must carefully be weighed against benefit. Policies vary throughout the United States, Australia, and Europe due to limited data on outcome and treatability of candidate screening conditions. We elaborated the rationale for decision making in 3-methylcrotonyl-coenzyme A (CoA) carboxylase deficiency (MCCD), which afflicts leucine catabolism, with reported outcomes ranging from asymptomatic to death. In Bavaria, we screened 677,852 neonates for 25 conditions, including MCCD, based on elevated concentrations of 3-hydroxyisovalerylcarnitine (3-HIVA-C). Genotypes of MCCA (MCCC1) and MCCB (MCCC2) were assessed in identified newborns, their relatives, and in individuals (n = 17) from other regions, and correlated to biochemical and clinical phenotypes. NBS revealed eight newborns and six relatives with MCCD, suggesting a higher frequency than previously assumed (1:84,700). We found a strikingly heterogeneous spectrum of 22 novel and eight reported mutations. Allelic variants were neither related to biochemical nor anamnestic data of our probands showing all asymptomatic or benign phenotypes. Comparative analysis of case reports with NBS data implied that only few individuals (< 10%) develop symptoms. In addition, none of the symptoms reported so far can clearly be attributed to MCCD. MCCD is a genetic condition with low clinical expressivity and penetrance. It largely represents as nondisease. So far, there are no genetic or biochemical markers that would identify the few individuals potentially at risk for harmful clinical expression. The low ratio of benefit to harm was pivotal to the decision to exclude MCCD from NBS in Germany. MCCD may be regarded as exemplary of the ongoing controversy arising from the inclusion of potentially asymptomatic conditions, which generates a psychological burden for afflicted families and a financial burden for health care systems.

Alleles↗
PubMed2005

Schimke-immuno-osseous dysplasia: new mutation with weak genotype-phenotype correlation in siblings.

Schimke-immuno-osseous dysplasia (SIOD) is a multisystem disorder with the following consistent clinical features: spondyloepiphyseal dysplasia with disproportional growth deficiency, nephrotic syndrome with focal and segmental glomerulosclerosis, and defective cellular immunity. Transitory ischemic attacks due to vaso-occlusive processes are complications in some patients with severe SIOD. Recently, mutations of SMARCAL1, which encodes a putative chromatin remodelling protein, have been associated with SIOD. Patients with milder disease were observed to harbor a missense mutation on each allele, whereas patients with a severe form of the disease were predicted to have at least one allele with a nonsense, frameshift or splicing mutation. We report two brothers who are both compound heterozygous for the mutations 836 T>C and 2542 G>T detected in exons 4 and 17, respectively. We demonstrate the lack of genotype-phenotype correlation in these patients as one brother shows some features of the severe form while the other does not. Neither clinical nor molecular findings can fully predict the clinical course of SIOD.

Adult↗
PubMed2005

Neonatal screening for defects of the mitochondrial trifunctional protein.

Long-chain l-3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency has been included in the routine neonatal screening program by the German screening commission. As tandem mass spectrometry (TMS) does not discriminate between the different defects of the mitochondrial trifunctional protein (MTP) screening for isolated LCHAD deficiency includes the detection of long-chain 3-ketoacyl-CoA thiolase and complete MTP deficiencies as well. We identified 11 patients with abnormalities of the MTP out of 1.2 million newborns screened in our laboratory during the last 6 years. Treatment was started on the day the screening result was obtained (day 3 to day 9 of life). Seven of these newborns developed satisfactorily during an observation period of up to 64 months. They had isolated LCHAD deficiency, four of them caused by the typical mutation (1528 G>C), three others had no molecular genetic analysis done or were shown to have previously unknown mutations. Four children did not survive, two of them showing complete deficiency of MTP and two showing deficiency of long-chain 3-ketoacyl-CoA thiolase. We conclude that, despite the rarity of the disease, screening for MTP deficiencies is justified based on the following criteria: improved quality of life for patients with isolated LCHAD deficiency, absence of stigmatisation of babies showing mild variants without necessity of treatment, no significant increase of the total number of false positive screening results, no false negative results to our knowledge. Finally, extension of analysis to MTP deficiencies is achieved without additional costs for screening laboratories already using TMS.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed2005

Mitochondrial function in schimke-immunoosseous dysplasia.

Schimke-immunoosseous dysplasia (SIOD) is a multisystemic disorder caused by a mutation of a putative chromatin remodelling protein. Spondyloepiphyseal dysplasia with disproportionate growth deficiency, nephrotic syndrome with focal and segmental glomerulosclerosis, defective cellular immunity, and transient ischemic attacks are major clinical features in the severe form of SIOD. In the present study we tested the hypothesis that mitochondrial dysfunction may be an underlying pathophysiologic mechanism in this multisystemic disease. Mitochondrial parameters were studied in blood (lactate, pyruvate, ketone bodies, alanine) and in urine (organic acids) of four patients with the severe form of SIOD. Activities of respiratory chain enzymes were measured spectrophotometrically in fibroblasts of two of these patients. In patients with the severe form of SIOD normal concentrations of lactate as well as normal lactate/pyruvate- and ketone-body ratios were found in plasma. Alanine, the long-term parameter for lactate, was normal as well; metabolites of the citrate cycle were not found in the urine. Activities of respiratory chain enzymes I-V were not significantly reduced in fibroblasts from two patients with the severe form of SIOD. There was no evidence for mitochondrial dysfunction in SIOD. The underlying pathophysiology of SIOD remains unclear.

Arteriosclerosis↗
PubMed2004

Generalized atherosclerosis sparing the transplanted kidney in Schimke disease.

Schimke-immuno-osseous dysplasia (SIOD) is a multisystem disorder caused by a mutation of the chromatin remodeling protein. The main clinical findings are spondyloepiphyseal dysplasia with disproportional growth deficiency, nephrotic syndrome with focal and segmental glomerulosclerosis, and defective cellular immunity. Transitory ischemic attacks due to vaso-occlusive processes are still an untreatable and life-limiting complication in patients with SIOD. The underlying pathophysiology of vaso-occlusive processes in SIOD is unclear. We report the clinical and pathological findings of the eldest published patient with the severe form of SIOD, who died at the age of 23 years due to pulmonary hypertension with subsequent right heart failure. The autopsy revealed a severe generalized atherosclerosis including the brain, heart, and pulmonary arteries. However, the kidney that was transplanted at the age of 5 years showed a good graft function without glomerular sclerosis and with only minimal nephrosclerosis on histology. Thus, the absence of severe vaso-occlusive processes in the transplanted organ and in the severely atherosclerotic host may indicate that the vaso-occlusive processes in SIOD are not caused by post-transplant cardiovascular morbidity such as arterial hypertension and hyperlipidemia. Instead, vascular factors of the host such as endothelial dysfunction may explain the pathophysiology of atherosclerosis in SIOD.

Adolescent↗
PubMed2004

3-methylglutaconic aciduria type I in a boy with fever-associated seizures.

3-Methylglutaconic-aciduria type I (MGA1, OMIM 250950) resulting from 3-Methylglutaconyl-coenzyme A hydratase deficiency is a rare inherited metabolic disorder of l-leucine catabolism. We diagnosed this condition in a 4-year-old German male with generalized fever-associated seizures from the age of 12 months and normal psychomotor development. First he was considered to suffer from uncomplicated febrile seizures. After his eighth seizure, laboratory investigations were performed to exclude inborn errors of metabolism. Analysis of organic acids in urine indicated highly elevated concentrations of 3-methylglutaconic and 3-hydroxyisovaleric acids. 3-Methylglutaconyl-coenzyme A hydratase activity was markedly decreased in skin fibroblasts. Mutation analysis in the AUH gene revealed homozygosity for a novel splice site mutation IVS9-2A>G. We conclude that MGA1 may be associated with fever-associated seizures even in children without delayed psychomotor development.

Amino Acid Metabolism, Inborn Errors↗
PubMed2004

Fabry disease: reduced activities of respiratory chain enzymes with decreased levels of energy-rich phosphates in fibroblasts.

UNLABELLED: Fabry disease (FD, MIM 301500) caused by a deficient activity of alpha-galactosidase A is characterized by intralysosomal storage of glycosphingolipids. Main clinical features are paresthesia, hypohidrosis, angiokeratoma, renal insufficiency, and cardiovascular or cerebral complications. The exact pathogenesis is unclear. Beside mechanical storage biochemical factors might play a role. As FD is a multisystemic disorder and mitochondrial dysfunction has been described in patients with neuronal ceroidlipofuscinosis (another lysosomal storage disease) we examined mitochondrial function in fibroblasts from patients with FD. RESULTS: Activities of respiratory chain enzymes I, IV, and V were significantly (p < 0.01) lower in FD-cells. Mitochondrial recovery was unchanged as judged by the activity of the mitochondrial marker enzyme citratesynthase, cellular protein content was not significantly different. CP, ADP, and AMP concentrations were significantly (p < 0.01) lower in FD-cells. ATP was slightly, but not significantly reduced (p = 0.045). CONCLUSION: Organ dysfunction in FD may not only be explained by mechanical storage of glycosphingolipids. As in NCL, lysosomal storage material may lead to mitochondrial dysfunction with a reduction of respiratory chain enzyme activities and a subsequent drop in cellular levels of energy-rich phosphates.

Adenine Nucleotides↗
PubMed2003

Neonatal screening for citrullinaemia.

UNLABELLED: In a period of 40 months (1st March 1999 to 30th June 2002) 610,000 blood samples were analysed in one screening centre for citrulline as a pilot study for neonatal screening using tandem mass spectrometry. Persistent hypercitrullinaemia (Cit >1.5 mg/dl or 85.5 micro mol/l, not corrected for recovery) was identified in 15 newborns. Four children were diagnosed with classical neonatal onset citrullinaemia and eight with persisting asymptomatic hypercitrullinaemia. In two asymptomatic newborns and in one symptomatic preterm patient, argininosuccinate lyase deficiency was identified as the cause of moderately elevated levels of citrulline (cases not described in this paper). Citrulline concentrations were only temporarily mildly elevated in two newborns and in these the results of the original neonatal screening were therefore regarded as false-positive; we did not find any other false-positives. The screening result allowed the introduction of immediate specific treatment in two cases of citrullinaemia and may have prevented metabolic decompensation in those with presumed mild citrullinaemia. In one child who developed severe hyperammonaemia on the 2nd day of life, sequelae could not be avoided. CONCLUSION: neonatal screening for citrullinaemia is more complex than expected and, with the actual logistics, results may be obtained too late in severe forms.

Argininosuccinic Aciduria↗
PubMed2003

BH4-sensitive hyperphenylalaninemia: new case and review of literature.

We report a patient with BH(4)-sensitive phenylketonuria. In neonatal screening, phenylalanine levels above 10 mg/dl were detected. In the tetrahydrobiopterin- (BH(4)) loading test, phenylalanine concentrations in serum fell significantly. Dihydropteridine reductase activity in blood, pterines, and neurotransmitters in cerebrospinal fluid, as well as pterines in urine were all normal. Mutation analysis revealed compound-heterozygosity for the mutations R408W and K320N. Under BH(4)-supplementation without a specific phenylalanine-reduced diet, phenylalanine-concentrations are in the therapeutic range and our patient developed normally.

Biopterins↗
PubMed2003

Regulation of the mitochondrial ATP-synthase in health and disease.

In most tissues the mitochondrial ATP-synthase plays a central role by synthesizing the bulk of ATP. According to the classical theory of respiratory control, flux through this enzyme is solely determined by substrate (ADP) concentration while the enzyme has a fixed capacity. However, in different cell types such as rat cardiomyocytes and neurons, dog heart, human fibroblasts, and skeletal and heart muscle from children, it has been shown that active regulation of the mitochondrial ATP-synthase in response to cellular energy demand exists. For example, in rat cardiomyocytes the mitochondrial ATP-synthase activity is down-regulated in response to anoxia or mitochondrial uncoupling. By this mechanism cellular ATP is conserved, as under these conditions the ATP-synthase would work in reverse and hydrolyze ATP. When cardiomyocytes are stimulated to contract, ATP-synthase activity is up-regulated in line with the increased energy demand. Preincubation of the cardiomyocytes with positive inotropic substances results in further up-regulation of the ATP-synthase. By blocking calcium transport, it has been shown that the up-regulation of the enzyme is calcium-dependent. On a molecular level, up-regulation is probably mediated by the calcium-binding inhibitor protein (CaBI) and down-regulation via the inhibitor protein IF(1). The ATP-synthase system is disturbed under several pathophysiological conditions. First, mutations can cause a primary defect in the mitochondrial ATP-synthase (respiratory chain defect). Furthermore, secondary defects of the ATP-synthase occur. In rat models abnormalities of ATP-synthase can be detected in different types of cardiomyopathy/heart hypertrophy. The changes are reversible in response to treatment of the heart diseases. Abnormalities of the ATP-synthase system can be observed in fibroblasts from patients with neuronal ceroidlipofuscinoses. Toxic metabolites accumulating in methylmalonic acidurias can inhibit ATP-synthase. When neurons are incubated with 3-OH glutarate - a substance accumulating in glutaric aciduria I-as a model for glutaric aciduria I, ATP-synthase activity is compromised. This lack of energy may lead to 'slow onset' excitotoxicity and finally cell death. Cells can be rescued by adding creatine to the incubation medium. In D-2-hydroxyglutaric aciduria, inhibition of the ATP-synthase has been observed.

Animals↗