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Biomedical subjects

W G Sherwood

Publications and source records attributed to W G Sherwood.

At least 19 recordsLinked to original sources

Long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency neuropathy: response to cod liver oil.

Docosahexaenoic acid (DHA) deficiency has recently been documented in several children with long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency (LCHADD). We studied a 13-year-old boy with LCHADD who had limb girdle myopathy, recurrent myoglobinuria, and progressive sensorimotor axonopathy with demyelination. At 11 years of age, he was started on cod liver oil extract, high in DHA content. Over 12 months, he demonstrated a marked clinical recovery. Nerve conduction studies (NCS) demonstrated reappearance of previously absent posterior tibial and peroneal nerve responses and the amplitudes on motor ulnar and median NCS markedly increased from 7- to 14-fold, respectively.

3-Hydroxyacyl CoA Dehydrogenases↗

Fetal polycystic kidney disease associated with glutaric aciduria type II: an inborn error of energy metabolism.

The findings of hyperechoic and enlarged fetal kidneys on routine antenatal ultrasonography is a non-specific finding that alerts the physician to a differential diagnosis of various genetic and non-genetic disorders, including fetal polycystic disease and Beckwith-Wiedeman syndrome. Detection of fetal or neonatal polycystic kidneys should alert the physician to the possibility of an associated lethal autosomal recessive inborn error of fatty acid metabolism known as multiple acyl-CoA-dehydrogenase defect (MADD). We report a case of fetal nephromegaly associated with rare inborn error of MADD. This case highlights the need for appropriate laboratory investigation of hyperechoic, enlarged fetal kidneys, and neonatal polycystic disease. The association of MADD with postnatally diagnosed polycystic disease of the kidney has been reported. The antenatal detection of nephromegaly followed by the subsequent postnatal diagnosis of MADD has not been previously reported. MADD should be considered in the differential diagnosis of this antenatal finding. Appropriate diagnostic procedures should be conducted, either pre- or postnatally, in order that appropriate genetic counseling may be provided for this autosomal recessively inherited disorder.

Acyl-CoA Dehydrogenases↗

Pancreatitis in patients with organic acidemias.

STUDY OBJECTIVE: The discovery of pancreatitis in two children with methylmalonic acidemia led us to review the experience with pancreatitis in a large number of patients with organic acidemias to determine whether pancreatitis is an important complication of these disorders. DESIGN: Case series. SETTING: Pediatric metabolism services at five tertiary care centers. PATIENTS: Records of all patients with organic acidemias followed at the five institutions during the past 10 years were reviewed. Pancreatitis was recognized by symptoms and laboratory findings and confirmed by imaging studies, surgery, or autopsy. At three institutions all cases of pancreatitis in children younger than 10 years were reviewed. MEASUREMENTS AND RESULTS: Nine children with pancreatitis (seven with acute and two with chronic cases) were identified among 108 children with branched-chain organic acidemias. They ranged in age from 13 months to 9 years. Five had methylmalonic acidemia, three had isovaleric acidemia, and one had maple syrup urine disease. There were three deaths; acute hemorrhagic pancreatitis occurred in two children, and chronic pancreatitis was found at autopsy in a third. All three patients with isovaleric acidemia and pancreatitis were identified after the occurrence of pancreatitis. The survey of pancreatitis at three institutions found 57 other patients (none with an inborn error) in addition to three patients with inborn errors included in this study. CONCLUSIONS: Acute or chronic pancreatitis may complicate branched-chain organic acidemias and must be considered in the assessment of patients with these disorders who have acute clinical deterioration and vomiting, abdominal pain, encephalopathy or shock, or milder symptoms. Conversely, an inborn error of organic acid metabolism should be considered in children with pancreatitis of unknown origin.

Acute Disease↗

Detection of metabolic disorders among selectively screened people with idiopathic mental retardation.

Fifth-eight people receiving residential or other services for idiopathic mental retardation were evaluated for evidence of metabolic disease. Five (8%) demonstrated persistent urinary organic acid abnormalities on at least three occasions, which pointed towards specific genetic metabolic defects. Instigation of specific treatment programs may have improved the quality of life for one of these participants. Appropriate genetic counseling was provided but could have been instigated much earlier had these investigations been performed as part of a routine workup for idiopathic mental retardation. This pilot study suggests a need for evaluation of other similar populations with idiopathic mental retardation.

Adolescent↗

Reliable prenatal diagnosis of Canavan disease (aspartoacylase deficiency): comparison of enzymatic and metabolite analysis.

Prenatal diagnosis has been undertaken in 17 pregnancies in 15 families at risk for aspartoacylase deficiency. Amniocentesis was at 14-18 weeks gestation followed by measurement of amniotic fluid N-acetyl-L-aspartate (NAA) levels in all pregnancies and amniocyte aspartoacylase activity in most pregnancies. In one case amniocentesis was performed at 11 weeks gestation in conjunction with chorionic villus sampling. At 14-18 weeks of gestation, control levels of NAA were 0.30-2.55 mumol/L. The fetus was predicted to be affected in 8 of the pregnancies, 4 of which were confirmed by enzyme analysis on fetal tissue and 2 by the clinical and metabolic expression of Canavan disease in a newborn. In two cases there was no fetal tissue available for enzyme confirmation. One of these had the highest amniotic fluid NAA level (8.68 mumol/L) and in the other pregnancy there were two amniocenteses, both with markedly elevated levels. Of 9 fetuses predicted to be normal, 8 newborns were clinically and biochemically normal. A single case with amniotic fluid NAA in the normal range (1.56 mumol/L, measured in one laboratory only) resulted in an aborted fetus in whom aspartoacylase was deficient in cultured skin fibroblasts. We propose that amniotic fluid NAA levels remain the best predictor of an affected fetus and recommend that the assay be performed in multiple laboratories.

Amniotic Fluid↗

3-Hydroxydicarboxylic and 3-ketodicarboxylic aciduria in three patients: evidence for a new defect in fatty acid oxidation at the level of 3-ketoacyl-CoA thiolase.

Three patients presented with evidence of a fatty acid oxidation disorder. Analysis of urinary organic acids by gas chromatography/mass spectrometry demonstrated the presence of medium-chain (C6-C12) dicarboxylic, 3-hydroxydicarboxylic, and 3-ketodicarboxylic acids in all three urines. 3-Ketodicarboxylic aciduria is reported for the first time here, as are the mass spectra for 3-ketosuberic, 3-ketosebacic, and 3-ketododecanedioic acids and the oximated spectrum for 3-ketoadipic acid. The presence of 3-ketodicarboxylic acids suggests a defect at the level of a long-chain 3-ketoacyl-CoA thiolase, an enzyme for which a deficiency state has not previously been described. Our patients may represent the first cases of a long-chain thiolase defect.

Acetyl-CoA C-Acyltransferase↗

Identification of urinary metabolites of (+/-)-2-(p-isobutylphenyl)propionic acid (Ibuprofen) by routine organic acid screening.

Ibuprofen [(+/-)-2-(p-isobutylphenyl)propionic acid] has recently been introduced as a pediatric anti-inflammatory agent. To determine how this agent interferes with urine organic acid analysis, an important pediatric investigation, we have analyzed urine from two subjects pre- and post-Ibuprofen dosage and two subjects on chronic Ibuprofen therapy. A distinctive pattern of drug interference on the organic acid profile was detected. There were three major components, corresponding to unmetabolized Ibuprofen and to the oxidation products hydroxy Ibuprofen and carboxy Ibuprofen. Therefore, the major mechanism of Ibuprofen metabolism appears to be microsomal, although mitochondrial and peroxisomal routes cannot be excluded. Laboratories carrying out routine organic acid analysis should be aware of the nature and magnitude of the organic aciduria caused by Ibuprofen.

Adult↗

Phenotypic heterogeneity in the syndromes of 3-methylglutaconic aciduria.

Combined 3-methylglutaconic and 3-methylglutaric aciduria, one of the more common urinary organic acid abnormalities, has been observed in at least three clinical syndromes. We studied an additional seven patients with 3-methylglutaconic aciduria, four of whom were best categorized as having the type II syndrome, two as having an "unspecified" syndrome, and one who may have had a primary urea cycle defect. In cultured cells and autopsy tissues derived from patients with the type II and unspecified syndromes, we were unsuccessful in identifying a defect in the leucine degradative pathway distal to 3-methylcrotonyl-coenzyme A carboxylase and in the cholesterol biosynthetic pathway between 3-hydroxy-3-methylglutaryl-coenzyme A reductase and diphosphomevalonate decarboxylase. Further assessment of the cholesterol biosynthetic pathway in several patients with one of the two types of disease also provided no defined abnormality. The primary metabolic defects in the type II and unspecified syndromes remain undefined.

Amino Acid Metabolism, Inborn Errors↗

Partial biotinidase deficiency associated with Coffin-Siris syndrome.

Coffin-Siris syndrome is an infrequent condition characterised by mental retardation, nail hypoplasia or absence with fifth digit involvement and feeding problems. In addition, sparse scalp hair and chronic intractable eczema has been described in this syndrome. We report a 26-month-old girl with the disease and partial biotinidase deficiency.

Alopecia↗

3-Oxothiolase activities and [14C]-2-methylbutanoic acid incorporation in cultured fibroblasts from 13 cases of suspected 3-oxothiolase deficiency.

Cultured fibroblasts from 13 patients with organic aciduria suggesting 3-oxothiolase deficiency were studied by measuring first the capacity of the isoleucine degradative pathways in whole cells, as the incorporation of 1-[14C]-2-methylbutanoic acid into macromolecules, and, second, the activity of 3-oxothiolase in cell homogenates using specific 3-oxoacyl-CoA substrates to identify the different enzymes. Nine patients showed low incorporation by the macromolecular labeling assay, as well as deficiency of 2-methylacetoacetyl-CoA thiolase. In this group of patients, low activity by the macromolecular labeling assay was associated with clinically severe symptoms, and vice versa. Two patients showed reduced macromolecular labeling, but apparently normal 3-oxothiolase. Finally, two patients showed normal activities by either test, the reason for their particular organic aciduria being unknown. In conclusion, occurrence of urinary 2-methyl-3-hydroxybutyric acid and/or tiglyglycine is not an unequivocal indicator of the absence of the thiolase that metabolizes 2-methylacetoacetyl-CoA. Measurement of 1-[14C]-2-methylbutanoic acid incorporation in cultured fibroblasts adds important information in studying possible defects of the isoleucine catabolic pathway.

Acetyl-CoA C-Acyltransferase↗

In utero central nervous system damage in pyruvate dehydrogenase deficiency.

Pyruvate dehydrogenase deficiency is among the most common causes of congenital lactic acidosis. We describe siblings with congenital lactic acidosis due to a deficiency of pyruvate dehydrogenase complex. The findings of computed tomography and pathologic studies suggest that central nervous system damage had occurred in utero. These observations have implications for treatment and outcome in patients with enzymatic defects causing congenital lactic acidosis.

Brain↗

Neonatal screening for biotinidase deficiency in north eastern Italy.

Biotinidase deficiency satisfies all the criteria for incorporation into neonatal mass screening programmes for inborn errors of metabolism. We report our preliminary experiences with screening of 24,300 newborns during a 6 month-period when 1 infant with biotinidase deficiency was detected. On the basis of these results, this disorder appears to be as common as other well known metabolic disorders for which mass screening is available.

Amidohydrolases↗

Cardiac manifestations in disorders of fat and carnitine metabolism in infancy.

The prognosis of patients with cardiomyopathy associated with hypocarnitinemia is uncertain. Cardiac hemodynamics, histologic findings and response to oral L-carnitine therapy were retrospectively evaluated in 11 children with cardiomyopathy associated with abnormal carnitine metabolism. Three had systemic carnitine deficiency, two familial hypocarnitinemia with neutropenia, three transient neonatal hypocarnitinemia and three a carnitine insufficiency syndrome. Six had a hypertrophic and five a dilated cardiomyopathy. Hypotonia was present in seven (64%). The cardiothoracic ratio was greater than 0.60 in eight (73%). The most frequent abnormality on the electrocardiogram was ST-T wave inversion in the left precordial leads with various degrees of left ventricular hypertrophy. Echocardiographically, two patients with hypertrophic cardiomyopathy had decreased left ventricular function and two patients with dilated cardiomyopathy had increased thickness of the left ventricular wall. Histologic evaluation (two autopsies and one endomyocardial biopsy) revealed striking lipid accumulation within hypertrophied myocytes. Six of eight patients on carnitine replacement therapy had improvement echocardiographically during a 3 month to 2 year follow-up period. In summary, both hypertrophic and dilated cardiomyopathy can result from abnormal carnitine metabolism. The determination of plasma carnitine concentrations and fatty acid metabolism by-products should be performed in all patients with either form of cardiomyopathy of unknown etiology because carnitine supplementation may lead to improvement.

Biopsy↗

Variable clinical presentation in patients with defective E1 component of pyruvate dehydrogenase complex.

Clinical findings are presented for 30 patients with lactic acidemia in whom activity of the pyruvate dehydrogenase complex in fibroblasts was significantly (P = less than 0.01) below that of control cell lines. Residual activity of the activated complex ranged from 1.6% to 68.5% of control activity. Seven patients died before 6 months of age, and another five before reaching 2 years of age. Sixteen of the surviving patients and the five who died between 6 months and 2 years all had psychomotor retardation. Seventeen children had structural central nervous system damage, as determined either by computed tomography or at autopsy. The extent and location of damage varied from cerebral atrophy to the development of cystic lesions in the cerebral cortex, basal ganglia, and brain stem. Two patients had ataxic episodes only and were not developmentally delayed. This cohort of patients strongly resembles a comparable group assembled from various other reports.

Acidosis, Lactic↗

Adult onset systemic carnitine deficiency: favorable response to L-carnitine supplementation.

We report the case of a patient who at age 39 first developed an episode of muscle weakness and transient ketoacidosis with biopsy proven fatty infiltration of the liver. Over the next several years, myopathy ensued; biopsy revealed extensive deposition of lipid globules in type 1 muscle fibres. Further investigations established the diagnosis of systemic carnitine deficiency (SCD) with skeletal muscle, hepatic, and cardiac involvement. The patient has benefited from L-carnitine supplementation. Our case represents an unusually late onset of SCD and highlights the necessity, when appropriate, of a high index of suspicion of this rare but treatable disorder.

Carnitine↗