Biotinidase deficiency

BACKGROUND: Biallelic pathogenic variants in SLC5A6 resulting in sodium-dependent multivitamin transporter (SMVT) defect have recently been described as a vitamin-responsive inborn error of metabolism mimicking biotinidase deficiency. To our knowledge, only 16 patients have been reported so far with various clinical phenotypes such as neuropathy and other neurologic impairments, gastro-intestinal dysfunction and failure to thrive, osteopenia, immunodeficiency, metabolic acidosis, hypoglycemia, and recently severe cardiac symptoms...

A 19-year-old man presented with 3 years of gradually progressive, painless vision loss in both eyes. The ophthalmic examination showed bilateral diminished visual acuity, dyschromatopsia, and temporal optic nerve pallor. The neurological examination was consistent with a mild myelopathy with decreased pin-prick sensation starting at T6-T7 and descending through the lower extremities. Hyperreflexia was also present in the lower more than upper extremities. Infectious, inflammatory, and nutritional serum workup and cerebrospinal fluid analysis were both unrevealing...

BACKGROUND: Biotinidase deficiency is caused by absent activity of the biotinidase, encoded by the biotinidase gene (BTD). Affected individuals cannot recycle the biotin, leading to heterogeneous symptoms that are primarily neurological and cutaneous. Early treatment with biotin supplementation can prevent irreversible neurological damage and is recommended for patients with profound deficiency, defined as enzyme activity <10% mean normal (MN). Molecular testing has been utilized along with biochemical analysis for diagnosis and management...

INTRODUCTION: Biotinidase deficiency (BD) is an inherited autosomal recessive metabolic disorder. BD has been associated with optic nerve atrophy, eye infections, and retinopathy. The most prevalent ophthalmic manifestation of BD is optic atrophy, which might be misdiagnosed as multiple sclerosis or neuromyelitis optica, especially in late-onset BD cases. METHODS: In this article, we report a 9-year-old boy with gradual vision loss. Ophthalmologic examination, Brain MRI, and several laboratory tests such as Aquaporin-4 IgG level and biotinidase level were done on the patient...

Diagnosis of Biotinidase deficiency (BTD) is extremely important to avoid several neurodevelopmental problems in early childhood. Colorimetric and fluorometric methods lack specificity and selectivity due to several interferences resulting in a high number of false positive results. We developed an HPLC method for BTD activity in serum with fluorescent detection. In colorimetric assays, biotinidase attacks the amide linkage of the artificial substrate biotinidyl-4-aminobenzoic acid (B-PABA) and releases p -aminobenzoic acid (PABA), which is converted to a purple dye by diazotization reaction...

Biotinidase deficiency (BD) is an autosomal recessive inherited metabolic disorder which results from the inability of biotin-dependent carboxylase enzymes to function due to the release and absorption of biotin, leading to neurological and cutaneous findings. In the present study, evaluation of demographic characteristics, clinical findings, laboratory results, molecular genetic characteristics, and genotype-phenotype correlations of cases with BD. Two hundred forty-seven cases were included in the study who were admitted to the Department of Pediatric Metabolism of Ankara Bilkent City Hospital after being identified with potential BD through the Newborn Screening Program (NBS), during family screening or based on suspicious clinical findings, or following the detection of a pathogenic variant in a BTD genetic analysis during the period of October 2020 and February 2022...

In this study, we have evaluated the underlying aetiologies, yield of genetic testing and long-term outcomes in patients with early-infantile developmental and epileptic encephalopathies. We have prospectively studied patients with seizure onset before 3 months of age. Based on the clinical details, neuroimaging, metabolic testing and comprehensive genetic evaluation, patients were classified into different aetiological groups. The phenotypic differences between genetic/unknown groups and remaining aetiologies were compared...

No abstract text is available yet for this article.

Biotinidase deficiency (BD) is an autosomal recessive inherited disorder of biotin recycling that leads to neurological and cutaneous consequences if left untreated. The clinical features of BD can be ameliorated or prevented by the administration of pharmacological doses of the vitamin biotin. Since it is a treatable disorder, BD is included in the newborn screening program in Türkiye as in many other countries. Therefore, monitoring of biotinidase enzyme activity (BEA) is of vital importance, especially for patients...

Whole-exome DNA sequencing is a rich source of clinically useful information for specialists, patients, and their families, as well as elucidating the genetic basis of monogenic and complex diseases in clinical diagnosis. However, interpreting and reporting variants encompassing exome and genome sequence analysis outcome data are one of the greatest challenges of the genomic era. In this study, we aimed to investigate the frequency and allele frequency spectrum of single nucleotide variants accepted as recessive disease carrier status in Turkish Cypriot exomes...

BACKGROUND: Biotinidase deficiency (BTD) is a rare autosomal recessive metabolic disease, which develops neurological symptoms because of the impaired biotin recycling. Pathogenic mutations on BTD gene cause BTD deficiency. The clinical features and mutation analysis of Pakistani children with BTD deficiency have rarely been described. Herein, for the first time, we report the clinical features, BTD gene mutations and biochemical analysis of seven symptomatic children with BTD deficiency from Pakistan...

OBJECTIVES: In the present study, we aimed to evaluate the genotype-phenotype relation in patients with biotinidase enzyme deficiency based on repeated biotinidase enzyme measurements. METHODS: The hospital file information of patients with biotinidase, enzyme deficiency was assessed retrospectively, and the relationship between the BTD gene mutations analysis results and biotinidase enzyme activity following the first and repeated enzyme activity assessments was analyzed...

OBJECTIVE: To evaluate quality indicators of the Neonatal Screening Referral Service of the state of Mato Grosso (NSRS-MT) from 2005 to 2019. METHODS: Cross-sectional, retrospective, exploratory, descriptive, and observational study from 2005 to 2019. The following parameters were analyzed: age of newborns at the first collection, time between sample collection and arrival at the laboratory, time between the arrival and release of results and time between requesting the second sample and arrival at the NSRS...

Biotinidase deficiency is a rare autosomal recessive neurometabolic disorder resulting in biotin deficiency. Our patient presented with seizures and developmental delay since infancy and was started on megavitamin supplements. At 14 years, she presented with motor regression with encephalopathy after discontinuation of vitamins. There were no skin and hair changes. Magnetic resonance imaging (MRI) of the brain showed bilateral symmetrical posterior putamen signal changes. Tandem mass spectroscopy showed increased methyl malonyl carnitine and 3-OH isovaleryl carnitine...

Learning points for clinicians Fornix is a white matter tract bundle that is a substantial component of the Papez Circuit and has memory and cognitive functions. Isolated bilateral fornix infarction is uncommon and the clinical presentation is memory impairments in general. Most cases are accompanied by vascular comorbidities such as pulmonary embolism and peripheral venous thrombosis. Here we presented an unusual case of bilaterally fornix infarction with biotinidase deficiency and presenting with paraparesis and acute onset anterograde amnesia...

Biotinidase (BTD) deficiency (OMIM 253260) is an autosomal recessively inherited metabolic disorder resulting from deficient activity of the BTD enzyme, which can cleave and release biotin from a variety of biotin-dependent carboxylases, and is therefore recognized as a tool to recycle biotin. Being a condition caused by variations on BTD gene with a consequence of free biotin shortage, BTD deficiency may impair the activity of biotin-dependent carboxylases, and thus bring about a buildup of potentially toxic compounds in the body, primarily 3-hydroxyisovaleryl-carnitine in plasma as well as 3-hydroxyisovaleric acid in urine...

No abstract text is available yet for this article.

UNLABELLED: Biotinidase deficiency (BTD) is an autosomal recessive disorder and causes the deficiency of four biotin-containing carboxylases. The prevalence is estimated at 1 in 60 000 births. BTD is associated with a wide spectrum of clinical manifestations, including abnormalities of the neurological, dermatological, immunological, and ophthalmological systems. Spinal cord demyelination as a manifestation of BTD has been infrequently described. CASE PRESENTATION: The authors present a case of 2...

BACKGROUND: Old age, obesity, and certain chronic conditions are among the risk factors for severe COVID-19. More information is needed on whether inherited metabolic disorders (IMD) confer risk of more severe COVID-19. We aimed to establish COVID-19 severity and associated risk factors in patients with IMD currently followed at a single metabolic center. METHODS: Among all IMD patients followed at a single metabolic referral center who had at least one clinic visit since 2018, those with accessible medical records were reviewed for SARS-CoV-2 tests...

Whole-exome sequencing (WES) is an excellent method for the diagnosis of diseases of uncertain or heterogeneous genetic origin. However, it has limitations for detecting structural variations such as InDels, which the bioinformatics analyzers must be aware of. This study aimed at using WES to evaluate the genetic cause of the metabolic crisis in a 3-day-old neonate admitted to the neonatal intensive care unit (NICU) and deceased after a few days. Tandem mass spectrometry (MS/MS) showed a significant increase in propionyl carnitine (C3), proposing methylmalonic acidemia (MMA) or propionic acidemia (PA)...