Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.12 (biotinidase)
 392 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with a newly recognised variant of biotinidase deficiency presented with acute bilateral visual loss at the age of 10 years. A progressive optic neuropathy, a predominantly motor type neuropathy and spastic paraparesis developed over the following 5 years. Metabolic investigations revealed biotin depletion causing multiple biotin dependent carboxylase deficiency. The basic defect was a biotin recycling disorder due to a biotinidase Km variant with residual colorimetric activity of 4.4% of normal. Further investigations on plasma biotinidase showed biphasic kinetics with two different reduced Vmax values and two Km-values, one being almost normal and the other highly elevated. After a period of 2 months of oral substitution with biotin 10 mg per day the visual field defects improved as well as the distal spastic parapareses and motor neuropathy. We conclude that the differential diagnosis of unexplained bilateral optic neuropathy of juvenile onset, particularly when associated with upper and lower motor neuron disease should include biotinidase deficiency.
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PMID:[Juvenile optic neuropathy caused by Km variants of biotinidase]. 131 91

The results are presented by the Austrian screening program for inborn errors of metabolism, which is one of the oldest and most comprehensive in the world. At present, the program comprises screening for the following diseases: phenylketonuria, galactosemia, homocystinuria, maple syrup urine disease, hypothyroidism, biotinidase deficiency. The results of the program with regard to diagnosed cases are presented: in total, 747 carriers of various inborn errors of metabolism have been detected by means of the Screening Program and were referred for therapy where appropriate.
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PMID:[25 years Austrian screening program for inborn errors of metabolism at the Vienna University]. 141 9

A patient with biotinidase deficiency and a progressive neurological disorder died just before the biochemical diagnosis was established. Post-mortem examination of the brain and spinal cord revealed necrotising lesions similar to those in Leigh's disease and Wernicke's encephalopathy. Unlike these two conditions, the regions affected included the hippocampus and parahippocampal cortex. In addition there was severe focal oedema in deep cerebral grey matter, the brain stem, and the spinal cord. These lesions appear to result from a number of severe metabolic disturbances, perhaps linked to an underlying disordered pyruvate metabolism. The nature of the pathology explains why a neurological deficit may persist despite treatment.
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PMID:Neuropathology of biotinidase deficiency. 144 28

Children with juvenile-onset multiple carboxylase deficiency lack biotinidase activity (biotinamide amidohydrolase, EC 3.5.1.12) in the liver and other tissues. Hence, little free biotin is metabolically available, resulting in seizures, acidosis, and serious neurological damage. As the absence of hepatic biotinidase activity is reflected in serum, assessment of biotinidase status can easily be made from a blood sample. A convenient qualitative procedure for screening infants has been employed in order to estimate serum levels of biotinidase in as little as 10 microliters of sample. This colorimetric procedure detects the formation of free p-aminobenzoate cleaved from the substrate, N-biotinyl-p-aminobenzoate at pH 6.0. The assay is easily performed and has a low incidence of false positive results. A kinetic assay for serum biotinidase has also been developed using biotinyl-p-nitroanilide (BpNA) as substrate. When 50 microliters of biotinidase positive serum was incubated with 0.2 mM BpNA in phosphate buffer at pH 6.0, an increase in absorbance was observed at 405 nm. The rate of change in absorbance was followed kinetically on the Roche Cobas BIO analyzer at 37 degrees C. Monitoring the increase in absorbance of para-nitroanilide every 60 seconds over 30 minutes demonstrated linearity from 10 to 30 minutes. In comparing results from this kinetic assay on 48 randomly selected sera with those obtained using a colorimetric procedure, a correlation coefficient of 0.85 was obtained. Several false positive results were observed in clearly lipemic sera.
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PMID:Neonatal screening for biotinidase deficiency. 150 82

Hypotonia was the initial symptom in four siblings from a nonconsanguineous Tunisian-Jewish family. Plasma carnitine was severely deficient, and urinary organic acid analysis revealed increased excretion of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. 3-Methylcrotonyl-coenzyme A carboxylase activity was reduced in skin fibroblasts; pyruvate carboxylase and serum biotinidase activities were normal. We conclude that 3-methylcrotonyl-coenzyme A carboxylase deficiency should be added to the list of metabolic causes of familial hypotonia of childhood.
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PMID:Familial hypotonia of childhood caused by isolated 3-methylcrotonyl-coenzyme A carboxylase deficiency. 151 17

We describe a method for more accurately determining residual biotinidase activity in sera of individuals with profound biotinidase deficiency. Using this method we found that there is a statistically significant difference in the means of residual serum enzyme activities of symptomatic children and those identified by newborn screening. A subgroup of children identified by screening have activities higher than any of the symptomatic population. These children may develop mild symptoms, may develop symptoms later in life, or may not develop symptoms at all.
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PMID:Comparison of profound biotinidase deficiency in children ascertained clinically and by newborn screening using a simple method of accurately determining residual biotinidase activity. 152 70

Children, especially infants, require adequate calories and nutrients to meet the high demands of normal growth and development; protein, essential fatty acids, vitamins and minerals are all important in achieving this goal. Malnutrition results from deficiency in one or more of these basic nutrients. It may be caused by (1) insufficient dietary intake, (2) malabsorption, (3) poor utilization of nutrients, and (4) increased catabolism. A range of clinical and metabolic changes occurs as a result of profound and generalized abnormalities at a cellular level. Mucocutaneous changes constitute one of the variable and multisystemic clinical manifestations of malnutrition. Although some signs are characteristic of a specific nutrient deficiency, an overlap of skin manifestations is observed in multiple deficiency states. The periorificial glazed erythema and hair loss of zinc deficiency also may be seen in patients with essential fatty acid deficiency, biotinidase deficiency, and even kwashiorkor. Mucous membrane changes associated with deficiency of many water-soluble vitamins may likewise be difficult to distinguish.
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PMID:Skin signs of nutritional disorders. 155 Jul 20

Newborn screening for biotinidase deficiency has identified children with profound biotinidase deficiency (less than 10% of mean normal activity) and about an equal number of children with partial biotinidase deficiency (10 to 30% of mean normal activity). Partial biotinidase deficiency was initially considered a variant without clinical consequences until one child, during an episode of gastroenteritis, developed symptoms of biotinidase deficiency that resolved with biotin therapy. Biochemical and immunologic characterization of biotinidase was performed in sera from 23 children with partial biotinidase deficiency from 19 families and 18 of their parents. As expected, all patients had cross-reacting material in their serum. Patients with partial biotinidase deficiency can be classified into six distinct biochemical phenotypes on the basis of the number of isoforms and the distribution frequency of the isoforms. Kinetic studies were performed on samples from 17 of the patients and were found to be normal in all cases. The patient with partial deficiency who became symptomatic has an isoform profile that is not different from 10 other asymptomatic, partially deficient children. The parents had normal isoform patterns. The isoform patterns observed in the patients with partial biotinidase deficiency were not different from those of the profoundly deficient patients who had cross-reacting material.
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PMID:Biochemical and immunologic characterization of serum biotinidase in partial biotinidase deficiency. 156 Oct 12

A case of a child with a biotinidase deficiency who had a laryngeal stridor as a leading symptom is presented. This rare disease is distressing for diagnosis but easily treatable, if recognized. This condition, unless suspect clinically, could easily be overlooked and unnecessary tracheotomy could be done.
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PMID:Biotinidase deficiency: a rare cause of laryngeal stridor. 159 65

In Portugal the screening for phenylketonuria (PKU) and congenital hypothyroidism (CH) was begun towards the end of 1979, and by 1990 59 cases of PKU and 227 cases of CH had been detected. The early initiation of treatment and the observed mental and motor development, point towards a normal development in these children. A trial screen for congenital adrenal hyperplasia was carried out in 100.000 newborns, from which it was concluded that, under the present conditions, screening at a national level is not justified. A similar study is currently being undertaken for biotinidase deficiency and cystic fibrosis. The results ares discussed, as are the cost/benefits evaluations.
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PMID:[National screening for phenylketonuria, congenital hypothyroidism and congenital adrenal hyperplasia]. 159 80


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