Biotinidase deficiency: Spectrum of molecular, enzymatic and clinical information from newborn screening Ontario, Canada (2007–2014)

Gannavarapu, Srinitya; Prasad, Chitra; DiRaimo, Jennifer; Napier, Melanie; Goobie, Sharan; Potter, Murray; Chakraborty, Pranesh; Karaceper, Maria D.; Muñoz, T. De Haro; Schulze, Andreas; MacKenzie, Jennifer; Li, Lihua; Geraghty, Michael T.; Al-Dirbashi, Osama Y.; Rupar, C. Anthony

doi:10.1016/j.ymgme.2015.08.010

Cited by 22 publications

(19 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…17 Only 7% of these (~1:50 000) neonates had a profound deficiency, compared with 1:137 401 reported by Wolf. The large difference between the worldwide survey and the incidence found in our study and others 16,[20][21][22][23][24][25][26][27][28] is likely due to considerable variation in the occurrence of this disorder across countries. Therefore, it is important for each country to study the incidence of biotinidase deficiency.…”

Section: Discussioncontrasting

confidence: 80%

“…17 More recent publications, however, indicate that the incidence of biotinidase deficiency ranges from 1:4500 to 1:62 500 in countries that screen for this disorder (eg, Brazil, the USA, Belgium, Germany and Greece). 16,[20][21][22][23][24][25][26][27][28] Our study shows that, in the Netherlands, 1 in 6100 to 1 in 8200 neonates had partial or profound biotinidase deficiency. 17 Only 7% of these (~1:50 000) neonates had a profound deficiency, compared with 1:137 401 reported by Wolf.…”

Section: Discussionmentioning

confidence: 54%

See 1 more Smart Citation

Neonatal screening for profound biotinidase deficiency in the Netherlands: consequences and considerations

et al. 2016

View full text Add to dashboard Cite

Section: Discussioncontrasting

confidence: 80%

Section: Discussionmentioning

confidence: 54%

Neonatal screening for profound biotinidase deficiency in the Netherlands: consequences and considerations

et al. 2016

View full text Add to dashboard Cite

“…Compound heterozygosity between one severe mutation and one of the next four less frequent mutations [c.968A>G (p.H323R), c.257T>G (p.M86R), c.310-15delT [8] and c.529G>A (p.E177K)] is likely to cause partial BD [9]. However, the association between the BTD genotype and biotinidase activity is not always consistent [10–13]. This disagreement may be due to the aforementioned factors that affect biotinidase activity or unknown factors, such as genetic variants in non-coding regions of the BTD gene.…”

Section: Introductionmentioning

confidence: 99%

Biotinidase deficiency: Genotype-biochemical phenotype association in Brazilian patients

et al. 2017

View full text Add to dashboard Cite

IntroductionThe association between the BTD genotype and biochemical phenotype [profound biotinidase deficiency (BD), partial BD or heterozygous activity] is not always consistent. This study aimed to investigate the genotype-biochemical phenotype association in patients with low biotinidase activity.MethodsAll exons, the 5'UTR and the promoter of the BTD gene were sequenced in 72 Brazilian individuals who exhibited low biotinidase activity. For each patient, the expected biochemical phenotype based on the known genotype was compared with the observed biochemical phenotype. Additional non-genetic factors that could affect the biotinidase activity were also analysed.ResultsMost individuals were identified by neonatal screening (n = 66/72). When consecutive results for the same patient were compared, age, prematurity and neonatal jaundice appeared to affect the level of biotinidase activity. The biochemical phenotype at the time of the second blood collection changed in 11/22 patients compared to results from the first sample. Three novel variants were found: c.1337T>C (p.L446P), c.1466A>G (p.N489S) and c.962G>A (p.W321*). Some patients with the same genotype presented different biochemical phenotypes. The expected and observed biochemical phenotypes agreed in 68.5% of cases (concordant patients). The non-coding variants c.-183G>A, c.-315A>G and c.-514C>T were present in heterozygosis in 5/17 discordant patients. In addition, c.-183G>A and c.-514C>T were also present in 10/37 concordant patients.ConclusionsThe variants found in the promoter region do not appear to have a strong impact on biotinidase activity. Since there is a disparity between the BTD genotype and biochemical phenotype, and biotinidase activity may be affected by both genetic and non-genetic factors, we suggest that the diagnosis of BD should be based on more than one measurement of plasma biotinidase activity. DNA analysis can be of additional relevance to differentiate between partial BD and heterozygosity.

show abstract

“…[52][53][54] Currently, all newborn screening programs in the United States and more than 30 other countries screen for biotinidase deficiency, with multiple recent studies suggesting that additional countries are considering incorporation of biotinidase deficiency into their newborn screening programs. [55][56][57][58][59][60] Historically, the screening method used was a colorimetric assay of biotinidase activity measured in dried blood spots, and states have individually established their own screening cutoffs and rescreening or follow-up protocols. 50 Commercial kits based on fluorescence are now available, and at this time no data are available regarding the frequency of use of the different assays across the United States.…”

Section: Newborn Screening For Biotinidase Deficiencymentioning

confidence: 99%

Laboratory diagnosis of biotinidase deficiency, 2017 update: a technical standard and guideline of the American College of Medical Genetics and Genomics

Strovel

Cowan

Scott

et al. 2017

Genetics in Medicine

View full text Add to dashboard Cite

Biotinidase deficiency is an autosomal recessively inherited disorder of biotin recycling that is associated with neurologic and cutaneous consequences if untreated. Fortunately, the clinical features of the disorder can be ameliorated or prevented by administering pharmacological doses of the vitamin biotin. Newborn screening and confirmatory diagnosis of biotinidase deficiency encompasses both enzymatic and molecular testing approaches. These guidelines were developed to define and standardize laboratory procedures for enzymatic biotinidase testing, to delineate situations for which follow-up molecular testing is warranted, and to characterize variables that can influence test performance and interpretation of results.

show abstract

Biotinidase deficiency: Spectrum of molecular, enzymatic and clinical information from newborn screening Ontario, Canada (2007–2014)

Cited by 22 publications

References 28 publications

Neonatal screening for profound biotinidase deficiency in the Netherlands: consequences and considerations

Neonatal screening for profound biotinidase deficiency in the Netherlands: consequences and considerations

Biotinidase deficiency: Genotype-biochemical phenotype association in Brazilian patients

Laboratory diagnosis of biotinidase deficiency, 2017 update: a technical standard and guideline of the American College of Medical Genetics and Genomics

Contact Info

Product

Resources

About