2 dez. Introdução: a deficiência de biotinidase é uma doença metabólica hereditária, com herança autossômica recessiva, causada por mutações no. Qué es la deficiencia de biotinidasa? ¿Qué es la deficiencia de biotinidasa? menu button. previous button. next button. Turn on your speakers. menu button. previous button. next button.

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Molecular characterisation and neuropsychological outcome of 21 patients with profound biotinidase deficiency detected by newborn screening and family studies. Development and characterization of a mouse with profound biotinidase deficiency: However, if the BTD pathogenic variants in the family have been identified, molecular testing is preferred.

Biotinidase Deficiency and BTD. Individuals with biotinidase deficiency may exhibit clinical features that are misdiagnosed as other disorders e. Ed Levy, Harvey L. Yearly evaluation by a clinical geneticist or metabolic specialist for individuals with profound deficiency and every two years for those with partial deficiency. Mutations in the BTD gene cause biotinidase deficiency.

Prenatal diagnosis for pregnancies biotinixasa increased risk for biotinidase deficiency is possible through measurement of biotinidase enzyme activity in cultured amniotic fluid cells and in amniotic fluid obtained by amniocentesis [ Secor McVoy et alChalmers et al ]. Sequence analysis detects variants that are benign, likely benign, of uncertain deficoencialikely pathogenic, or pathogenic.

Biotinidase deficiency

Chapter Notes Author Notes The author’s laboratory was the first defficiencia describe biotinidase deficiency in individuals with late-onset multiple carboxylase deficiency and has characterized the clinical, biochemical, and molecular features of the disorder.

Metabolic disorders of vitaminscoenzymes, and cofactors. Those with absence of all biotinidase enzyme activity are likely to be at ce risk for earlier onset of symptoms. Almost all children with profound biotinidase deficiency become symptomatic or are at risk of becoming symptomatic if not treated.


The following section deals with genetic risk assessment and the use of family history and genetic testing to clarify genetic status for family members.

See Molecular Genetics for information on allelic variants detected in this gene. Ophthalmologic findings in biotinidase deficiency.

Individuals with partial biotinidase deficiency may have hypotonia, skin rash, and hair loss, particularly during times of stress. Biotinidase deficiency can be excluded as a cause by determining biotinidase enzyme activity in serum. Children or adults with untreated partial biotinidase deficiency may exhibit any of the above signs and symptoms, but the manifestations are mild and occur only when the person is stressed, such as with a prolonged infection.

Potential for prenatal diagnosis of biotinidase deficiency. Clinical issues and frequent questions about biotinidase deficiency.

To administer biotin to an infant or young child, the tablet can be crushed or the contents of the capsule can be mixed with breast milk or formula in a spoon, medicine dispenser, or syringe. Methods that may be used include: The risk of biotinidase deficiency occurring in the offspring of an individual with biotinidase deficiency is essentially zero if the reproductive partner is not heterozygous deficiencix a BTD pathogenic variant.

: Deficiencia de biotinidasa

See Quick Reference for an explanation of nomenclature. Molecular genetic testing is performed by single- gene testing. Thoroughly cooked eggs present no problem because heating inactivates avidin, rendering it incapable of binding biotin. If left untreated, the disorder can rapidly lead to coma and death.

The age of onset of symptoms may be useful for distinguishing between holocarboxylase synthetase deficiency and biotinidase deficiency.

Another function of the biotinidase enzyme is to recycle biotin from enzymes that are important in metabolism processing of substances in cells. Once vision problems, hearing loss, and developmental delay occur, they are usually irreversible, even with ddficiencia therapy. Biotinidase is essential for the recycling of the vitamin biotin [ Wolf et al a deficiebcia.


Carrier testing for at-risk family members and prenatal testing for pregnancies at increased risk are options if the pathogenic variants in the family are known. The author’s laboratory was the first to describe biotinidase deficiency in individuals with late-onset multiple carboxylase deficiency and has characterized the clinical, biochemical, and molecular features of the disorder. In the United States, molecular prenatal testing is available and preferred.

For issues to consider in interpretation of sequence analysis results, click here.

Organic aciduria usually with the metabolites commonly seen in multiple carboxylase deficiency; however, 3-hydroxyisovalerate may be the only metabolite present. Biotinidase and its roles in biotin metabolism. Preliminary Laboratory Findings The following findings are sugggestive of biotinidase deficiency: A biotinidase Km variant causing late onset bilateral optic neuropathy.

Physical examination for neurologic findings e. Biotinidase deficiency can be found by genetic testing. American Journal of Medical Genetics. Late-Onset Multiple Carboxylase Deficiency. Braz J Med Biol Res. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that i credit for source http: Technical standards and guidelines for the diagnosis of biotinidase deficiency.

Recovery from neurological deficits following biotin treatment in a biotinidase Km variant. It is possible that these individuals would become symptomatic if stressed, such as with a prolonged infection.