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.
METHODS: We describe a case report of a 5-month-old girl presenting two recurrent episodes of metabolic decompensation and massive cardiac failure in the course of an infectious disease. We compare clinical, biological, and genetic findings of this patient to previous literature collected from Pubmed database (keywords: Sodium-dependent multivitamin transporter (SMVT), SMVT defect/disorder/deficiency, SLC5A6 gene/mutation).
RESULTS: We highlight the life-threatening presentation of this disease, the stagnation of psychomotor development, the severe and persistent hypogammaglobulinemia, and additionally, the successful clinical response on early vitamin supplementation (biotin 15 mg a day and pantothenic acid 100 mg a day). Metabolic assessment showed a persistent increase of urinary 3-hydroxyisovaleric acid (3-HIA) as previously reported in this disease in literature.
CONCLUSIONS: SMVT deficiency is a vitamin-responsive inborn error of metabolism that can lead to a wide range of symptoms. Increased and isolated excretion of urinary 3-hydroxyisovaleric acid may suggest, in the absence of markedly reduced biotinidase activity, a SMVT deficiency. Prompt supplementation with high doses of biotin and pantothenic acid should be initiated while awaiting results of SLC5A6 sequencing as this condition may be life-threatening.

Biotin is a water-soluble B-vitamin with key roles in metabolism and are found in most foods at low concentrations. Symptomatic biotin deficiency is rare, and few studies have investigated biotin requirements in relation to health outcomes. Data to support the setting of dietary reference values for biotin are limited.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: Bilateral optic atrophy and impaired visual acuity were detected on examination. The patient had a biotin level of 1.25 U/min/ml (normal range 3-9 U/min/ml), favoring the BD.
UNASSIGNED: In this study, we report a 9-year-old boy with vision loss diagnosed with BD. We also reviewed the literature to highlight the ophthalmic manifestations of BD. Ophthalmologists must consider BD in children with unexplained ophthalmologic complaints, especially when other characteristic signs of BD (e.g., developmental delay, seizure) are present. Also, patients with BD should undergo regular annual ophthalmologic examinations to be checked for any signs of eye involvement.

Biotin-thiamine-responsive basal ganglia disease (BTBGD) is a rare autosomal recessive neurometabolic disorder that is caused by biallelic pathogenic SLC19A3 variants and is characterized by subacute encephalopathy associated with confusion, convulsions, dysphagia, dysarthria, or other neurological manifestations.
A retrospective review of the data registry in Kuwait Medical Genetics Center for all cases diagnosed clinically and radiographically and confirmed genetically with BTBGD.
Twenty one cases from 13 different families were diagnosed with BTBGD in Kuwait. Most cases (86%) presented with confusion, dystonia, convulsions, or dysarthria, while three individuals were diagnosed pre-symptomatically during familial targeted genetic screening. Symptoms resolved completely within 2-week of treatment in two-thirds of the symptomatic cases but progressed in six of them to a variety of severe symptoms including severe cogwheel rigidity, dystonia and quadriparesis due to delayed presentation and management. Neuroradiological findings of the symptomatic cases revealed bilateral central changes in the basal ganglia. Two novel homozygous missense SLC19A3 variants were detected in a Kuwaiti and a Jordanian individuals, in addition to the previously reported Saudi founder homozygous variant, c.1264A > G; p.(Thr422Ala) in the remaining cases. Age of diagnosis ranged from newborn to 32 years, with a median age of 2-3 years. All cases are still alive receiving high doses of biotin and thiamine.
This is the first study reporting the phenotypic and genotypic spectrum of 21 individuals with BTBGD in Kuwait and describing two novel SLC19A3 variants. BTBGD is a treatable neurometabolic disease that requires early recognition and treatment initiation. This study highlights the importance of performing targeted molecular testing of the founder variant in patients presenting with acute encephalopathy in the region.

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BACKGROUND: Biotin is a commonly used supplement for hair, nail, and skin. Recent literature suggests that high-dose biotin therapy for neurological diseases like Multiple sclerosis can interfere with lab results that use biotin/streptavidin immunoassay, called biotin interference. Biotin interference can affect thyroid lab results, giving biochemical hyperthyroidism.
METHODS: Our patient, a 64-year-old white man with a known history of multiple sclerosis, presented with elevated free T3, free T4, and low TSH that resembled hyperthyroidism. He had no symptoms of hyperthyroidism except some fatigue and tachycardia on the first encounter. He was started on anti-thyroid medications. He was then re-evaluated since his lab results remained the same after two months of anti-thyroid medications. It was found that he was on biotin, 10000mcg/day, for his multiple sclerosis. Biotin was discontinued, and five days later his lab results returned to normal values.
CONCLUSIONS: The lack of knowledge of biotin use by patients can lead to misdiagnosis of patients\' thyroid lab results and improper management. Awareness about biotin interference and abnormal thyroid lab values should be a priority among clinicians and the public. If the biotin is discontinued on time, such misdiagnosis can be avoided.

Biotin thiamine responsive basal ganglia disease (BTRBGD) is an inherited autosomal recessive disorder that results from the inability of thiamine to cross the blood-brain barrier. It is considered a treatable condition if vitamin supplementation, most commonly with thiamine and biotin, is initiated early. BTRBGD can present as an infantile form, classical childhood form, or adult Wernicke-like encephalopathy. The infantile form is often the most severe and portends a worse prognosis with high mortality despite vitamin supplementation. We present a two-month-old who presented with irritability, opisthotonos, and abnormal eye movements who was found to have compound heterozygous variants in the SLC19A3 gene inherited in trans, including one known pathogenic intronic variant and a novel variant presumed to be pathogenic. She was therefore diagnosed with infantile BTRBGD. In this report, we discuss the differential for infantile BTRBGD, the clinical and radiologic features of BTRBGD, and describe a rapid, positive response to early vitamin supplementation in an infant with a likely pathogenic novel variant in SLC19A3.

UNASSIGNED: Biotin is a water-soluble vitamin acting as a covalently bound coenzyme in regulating energy production. Previous studies have reported that biotin supplementation may influence blood glucose and lipid level in patients with type 2 diabetes mellitus (T2DM).
UNASSIGNED: We searched Pubmed, Embase, and Cochrane library databases up to 8th August 2022 for studies examining the effects of biotin supplementation in T2DM patients. Pooled effects were measured by weighted mean differences (WMDs) with 95% confidence intervals (CI) using random effects models. Inter-study heterogeneity was assessed and quantified.
UNASSIGNED: A total of five random controlled trials (RCT), involving 445 participants were included. It was suggested that biotin supplementation for 28 to 90 days significantly decreased the level of fasting blood glucose (FBG) (MD: -1.21 mmol/L, 95% CI: -2.73 to 0.31), total cholesterol (TC) (MD: -0.22 mmol/L, 95% CI: -0.25 to -0.19) and triglycerides (TG) (MD: -0.59 mmol/L, 95% CI: -1.21 to 0.03). No significant beneficial effects were observed on insulin (MD: 1.88 pmol/L 95% CI: -13.44 to 17.21). Evidence for the impact of biotin supplementation on the levels of glycated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and very low-density lipoprotein cholesterol (VLDL-C) was limited to draw conclusion.
UNASSIGNED: Biotin supplementation may decrease FBG, TC and TG levels. However, its influence on insulin is not significant and further studies on the effects of biotin on HbA1c, LDL-C, HDL-C and VLDL-C are expected.

World Health Organization estimates that 30-50% of cancers are preventable by healthy lifestyle choices, early detection and adequate therapy. When the conventional therapeutic strategies are still regulated by the lack of selectivity, multidrug resistance and severe toxic side effects, nanotechnology grants a new frontier for cancer management since it targets cancer cells and spares healthy tissues. This review highlights recent studies using biotin molecule combined with functional nanomaterials used in biomedical applications, with a particular attention on biotinylated chitosan-based nanosystems. Succinctly, this review focuses on five areas of recent advances in biotin engineering: (a) biotin features, (b) biotinylation approaches, (c) biotin functionalized chitosan based nanosystems for drug and gene delivery functions, (d) diagnostic and theranostic perspectives, and (e) author\'s inputs to the biotin-chitosan based tumour-targeting drug delivery structures. Precisely engineered biotinylated-chitosan macromolecules shaped into nanosystems are anticipated to emerge as next-generation platforms for treatment and molecular imaging modalities applications.

BACKGROUND: Biotin may activate the acetyl-CoA-, 3-methylcrotonyl-CoA-, propionyl-CoA-, and pyruvate carboxylases to increase myelin repair and/or synthesis, and may enhance the production of adenosine triphosphate (ATP), which may be essential to prevent neurodegeneration. The purpose of this review was to determine the effectiveness and safety of high-dose biotin (HDB) in multiple sclerosis via a systematic review of randomized controlled trials.
METHODS: We searched the following electronic databases for relevant articles: MEDLINE, CENTRAL, EMBASE, Scopus, and ClinicalTrials.gov website until April 2021. We considered randomized clinical trials (RCTs) that involved adult patients diagnosed with any phenotype of multiple sclerosis that conforms with the McDonald 2010/2017 criteria or the Lublin 2014 criteria. We included studies employing high-dose biotin or \"MD1003\" administered orally for at least 300 mg/day and given for at least three months. The methodological quality assessment of the included studies was done using the Cochrane Risk of Bias (RoB) tool. The GRADE approach was used to assess the certainty of evidence [COE].
RESULTS: Out of 366 records identified, three RCTs involving 889 individuals diagnosed with MS (830 participants had progressive MS (PMS); 59 had RRMS) were pooled for analyses. The overall female:male ratio was 1.16:1. All included trials used HDB as an adjunctive treatment. The risks of bias in the three studies were low across the domains. At 12 to 15 months, there is insufficient evidence that the HDB and placebo arms differed in terms of composite improvement of MS-related disability (relative risk (RR) 2.87; 95% CI 0.29-28.40; 2 trials; 796 participants; I2 = 66%) [low COE], improvement in expanded disability status scale (IEDSS) (RR 2.27; 95% CI 0.25-20.98; 2 trials; 796 participants; I2 = 63%) [low COE], and both IEDSS and improvement in 25-foot walk time (ITW25) (IEDSS-ITW25) (RR 0.58; 95% CI 0.17-2.00; 2 trials; 796 participants; I2 = 13%) [moderate COE] among patients with PMS. Pooled data for ITW25 at 12 to 15 months yielded statistical significance (RR 2.06; 95% CI 1.04-4.09; 2 trials; 796 participants; I2 = 0%) [moderate COE] favoring HDB among patients with PMS. At 12 to 15 months, no significant differences were found in terms of mean change in EDSS (MD -0.06; 95% CI -0.14-0.02; 2 studies; 796 participants; 889 participants; I2 = 68%) among patients with PMS. Synthesized data on incidence of any AEs (RR 0.98; 95% CI 0.92-1.04; 3 trials; I2 = 0%) [high COE] and any serious AEs (RR 0.98; 95% CI 0.77-1.24; 3 trials; 889 participants; I2 = 0%) [moderate COE] were not significantly different between HDB and placebo groups. Out of 662 pooled patients in the HDB group, 31 patients (4.7%) were found to have laboratory test interference compared to zero event in the pooled placebo group [high COE].
CONCLUSIONS: A moderate certainty of evidence suggests a potential benefit in favor of HDB administered for 12 to 15 months in terms of ITW25 in patients with PMS. However, an important trade-off of this benefit is the high certainty of evidence suggesting an increased incidence of laboratory test interference when HDB is taken.