Genetic and phenotypic landscape of pediatric-onset epilepsy in 142 Indian families: Counseling and therapeutic implications.

The application of genomic technologies has led to unraveling of the complex genetic landscape of disorders of epilepsy, gaining insights into their underlying disease mechanisms, aiding precision medicine, and providing informed genetic counseling. We herein present the phenotypic and genotypic insights from 142 Indian families with epilepsy with or without comorbidities. Based on the electroclinical findings, epilepsy syndrome diagnosis could be made in 44% (63/142) of the families adopting the latest proposal for the classification by the ILAE task force (2022). Of these, 95% (60/63) of the families exhibited syndromes with developmental epileptic encephalopathy or progressive neurological deterioration. A definitive molecular diagnosis was achieved in 74 of 142 (52%) families. Infantile-onset epilepsy was noted in 81% of these families (61/74). Fifty-five monogenic, four chromosomal, and one imprinting disorder were identified in 74 families. The genetic variants included 65 (96%) single-nucleotide variants/small insertion-deletions, 1 (2%) copy-number variant, and 1 (2%) triplet-repeat expansion in 53 epilepsy-associated genes causing monogenic disorders. Of these, 35 (52%) variants were novel. Therapeutic implications were noted in 51% of families (38/74) with definitive diagnosis. Forty-one out of 66 families with monogenic disorders exhibited autosomal recessive and inherited autosomal dominant disorders with high risk of recurrence.

Comparison of microparticle transport and deposition in nasal cavity of three different age groups.

Objective: The nasal cavity effectively captures the particles present in inhaled air, thereby preventing harmful and toxic pollutants from reaching the lungs. This filtering ability of the nasal cavity can be effectively utilized for targeted nasal drug delivery applications. This study aims to understand the particle deposition patterns in three age groups: neonate, infant, and adult.Materials and methods: The CT scans are built using MIMICS 21.0, followed by CATIA V6 to generate a patient-specific airway model. Fluid flow is simulated using ANSYS FLUENT 2021 R2. Spherical monodisperse microparticles ranging from 2 to 60 µm and a density of 1100 kg/m3 are simulated at steady-state and sedentary inspiration conditions.Results: The highest nasal valve depositions for the neonate are 25% for 20 µm, for infants, 10% for 50 µm, 15% for adults, and 15% for 15 µm. At mid nasal region, deposition of 15% for 20 µm is observed for infant and 8% for neonate and adult nasal cavities at a particle size of 10 and 20 µm, respectively. The highest particle deposition at the olfactory region is about 2.7% for the adult nasal cavity for 20 µm, and it is <1% for neonate and infant nasal cavities.Discussion and conclusions: The study of preferred nasal depositions during natural sedentary breathing conditions is utilized to determine the size that allows medication particles to be targeted to specific nose regions.

Standardizing Minimally Invasive Tissue Sampling of Postmortem Brain Using Bard Monopty Needle in Newborns with Neurological Injury.

INTRODUCTION: Minimally invasive tissue sampling of the brain in newborns using the Bard Monopty needle helps to diagnose various neurological conditions by obtaining relevant brain cores. We designed a modified procedure to provide maximum diagnostic utility in brain tissue biopsies. METHOD: Twenty newborns underwent postmortem minimally invasive tissue sampling of the brain through the anterior fontanelle and posterior approach, using the engraved lines on the needle labeled from mark 0 to 13. The cores were correlated with conventional autopsy findings. RESULTS: Meninges were best obtained at marks 0 and 1 from the anterior fontanelle and mark 1 from posterior fontenelle in 85% of cases. Periventricular brain parenchyma was best obtained from mark 3 and mark 1 from anterior and posterior fontanel, respectively in 90% cases. The sampling success in obtaining brain cores was 100%. DISCUSSION: This modified technique increases the yield of meninges and brain tissue in newborns and aids in diagnosis.

Community perceptions of postmortem examination and minimally invasive tissue sampling in neonates:a qualitative study in South India.

BACKGROUND: Postmortem examination is the gold standard for establishing the cause of death. Minimally Invasive Tissue Sampling (MITS) of organs is a novel approach that can be used as an alternative to postmortem examination. In this study, the community perceptions in two states in South India towards neonatal postmortem and the acceptance towards the MITS technique is studied. METHODS: In-depth interviews were conducted among the participants from Kerala and Karnataka to understand the perception towards postmortem and the acceptance of the novel MITS technique. The interviews were audio recorded, and a thematic analysis was done to identify the overarching themes and codes. RESULTS: The knowledge and attitude of participants on conventional and MITS postmortem techniques, reasons for refusal, and the need for raising awareness were identified in the study. Participants favored the MITS techniques as it was less disfiguring and less time-consuming. The major concerns for refusal of conventional postmortem were that the procedure was disfiguring, time-consuming, and caused emotional stress to the parents. CONCLUSIONS: Participants favored the MITS approach over conventional postmortem as it caused less disfigurement and was conducive to the religious practice of burial of the body.

Pharmacometric approach to assist dosage regimen design in neonates undergoing therapeutic hypothermia.

BACKGROUND: Therapeutic hypothermia (TH) is the treatment of choice for neonates diagnosed with perinatal asphyxia (PA). Dosing recommendations of various therapeutic agents including antimicrobials were not specifically available for the neonates undergoing TH. METHODS: A systematic search methodology was used to identify pharmacokinetic (PK) studies of antimicrobials during TH. Antimicrobials with multiple PK studies were identified to create a generalizable PK model. Pharmacometric simulations were performed using the PUMAS software platform to reproduce the results of published studies. A suitable model that could reproduce the results of all other published studies was identified. With the help of a generalizable model, an optimal dosage regimen was designed considering the important covariates of the identified model. RESULTS: With the systematic search, only gentamicin had multiple PK reports during TH. A generalizable model was identified and the model predictions could match the reported/observed concentrations of publications. Birth weight and serum creatinine were the significant covariates influencing the PK of gentamicin in neonates. A dosage nomogram was designed using pharmacometric simulations to maintain gentamicin concentrations below 10 µg/mL at peak and below 2 µg/mL at trough. CONCLUSIONS: A generalizable PK model for gentamicin during TH in neonates was identified. Using the model, a dosing nomogram for gentamicin was designed. IMPACT: Dosing guidelines for antimicrobials during TH in neonates is lacking. This is the first study to identify the generalizable model for gentamicin during TH in neonates. Nomogram, proposed in the study, will aid the clinicians to individualize gentamicin dosing regimen for neonates considering the birth weight and serum creatinine.

Designing a mobile health intervention for preterm home care: Application of conceptual framework.

Mobile health (mHealth) solutions are being widely explored in low- and middle-income countries (LMICs) due to its scope in reducing the healthcare access gap and improving health outcomes. The fit of mHealth solutions to specific users and their viability in a particular setting plays a significant role in the successful adoption and sustainable implementation. This article describes the process of designing a sustainable mHealth application for delivering preterm home care to babies discharged from the neonatal intensive care unit (NICU) in India. Intended end-users are the parents, who are primary caregivers at home, especially mothers of preterm babies and healthcare providers who cared for them at the hospital. This mHealth application is designed to facilitate continuity of care for these preterm babies transitioning from an intensive healthcare setting to home with unique and complex health care needs. It is equipped to remotely monitor the growth and development for early detection of growth impairment and developmental delay often seen in preterm babies in their early years. Therefore, a mHealth application was designed applying a relevant conceptual framework for successful adoption and an ecological model for sustainability in the Indian setting.

Cause of Death in Neonates With Neurological Insults in the Neonatal Intensive Care Unit: Insights From A MITS Pilot Study.

BACKGROUND: Minimally invasive tissue sampling (MITS) of organs has been used as an alternative to complete diagnostic autopsy in countries where refusal for autopsy in newborns is common for sociocultural reasons. There is a paucity of literature regarding the diagnostic utility of MITS of the brain after death in neonates with neurological insults, especially in India. METHODS: This was a prospective, preliminary single-center tertiary care hospital study in India, focused specifically on MITS of the brain after neonatal death as a diagnostic tool to identify the various neurological insults. All neonatal deaths with neurological symptoms occurring within the first 30 days of life were enrolled, irrespective of the suspected clinical diagnosis. RESULTS: Sixteen neonates were enrolled after death for MITS of the brain, performed for diagnostic purposes, during the study period from February 2020 to March 2021. Their gestational ages ranged from 26 to 38 weeks. All neonates had either a history of seizures and/or respiratory distress or clinical evidence of sepsis and were on ventilator support. Histopathology in all 16 neonates showed evidence of anoxia, with or without reactive astrogliosis or microgliosis. In 5 neonates with cranial ultrasound evidence of brain hemorrhage, MITS of the brain showed intraventricular hemorrhage, subdural hemorrhage, or intraparenchymal white matter microhemorrhages. Premortem blood culture-proven sepsis was seen in 9 neonates. In all cases (100%), MITS had a good diagnostic yield and was useful to establish the neurological insult in the brain. CONCLUSIONS: MITS of the brain provides an accurate and adequate diagnosis and can be an alternative to complete diagnostic autopsy for establishing the cause of death due to neurological insults, especially in low-resource settings where obtaining consent for more invasive procedure is often challenging.

Clinical and genetic spectrum of 104 Indian families with central nervous system white matter abnormalities.

Genetic disorders with predominant central nervous system white matter abnormalities (CNS WMAs), also called leukodystrophies, are heterogeneous entities. We ascertained 117 individuals with CNS WMAs from 104 unrelated families. Targeted genetic testing was carried out in 16 families and 13 of them received a diagnosis. Chromosomal microarray (CMA) was performed for three families and one received a diagnosis. Mendeliome sequencing was used for testing 11 families and all received a diagnosis. Whole exome sequencing (WES) was performed in 80 families and was diagnostic in 52 (65%). Singleton WES was diagnostic for 50/75 (66.67%) families. Overall, genetic diagnoses were obtained in 77 families (74.03%). Twenty-two of 47 distinct disorders observed in this cohort have not been reported in Indian individuals previously. Notably, disorders of nuclear mitochondrial pathology were most frequent (9 disorders in 20 families). Thirty-seven of 75 (49.33%) disease-causing variants are novel. To sum up, the present cohort describes the phenotypic and genotypic spectrum of genetic disorders with CNS WMAs in our population. It demonstrates WES, especially singleton WES, as an efficient tool in the diagnosis of these heterogeneous entities. It also highlights possible founder events and recurrent disease-causing variants in our population and their implications on the testing strategy.

Neonatal PT Improves Neurobehavior and General Movements in Moderate to Late Preterm Infants Born in India: An RCT.

PURPOSE: To examine whether a structured neonatal physical therapy program (SNP) improves neurobehavior and general movements in moderate to late preterm (MLP) infants. METHODS: Sixty MLP infants participated in this clinical trial. After baseline assessment using the Neurobehavioral Assessment of Preterm Infant (NAPI) and Prechtl General Movements (GMs) Assessment, infants were randomly allocated to a usual care (n = 30) or an SNP group (n = 30) and continued receiving usual care. The SNP group received intervention for 90 minutes/day, 6 days/week until discharge. Changes in neurobehavior and GMs were assessed at hospital discharge. RESULTS: Changes in scores on scarf sign and motor development and vigor clusters of NAPI document an improvement in the SNP group. The proportion of infants with poor repertoire GMs also decreased more in the SNP group than in the usual care group. CONCLUSION: The SNP may be effective in improving some aspects of neurobehavior and quality of GMs in MLP infants. WHAT THIS ADDS TO THE EVIDENCE: The addition of a structured neonatal physical therapy program to usual care can promote neurobehavioral organization and improve the quality of general movements in moderate and late preterm infants in India.

NAD(P)HX dehydratase (NAXD) deficiency: a novel neurodegenerative disorder exacerbated by febrile illnesses.

Physical stress, including high temperatures, may damage the central metabolic nicotinamide nucleotide cofactors [NAD(P)H], generating toxic derivatives [NAD(P)HX]. The highly conserved enzyme NAD(P)HX dehydratase (NAXD) is essential for intracellular repair of NAD(P)HX. Here we present a series of infants and children who suffered episodes of febrile illness-induced neurodegeneration or cardiac failure and early death. Whole-exome or whole-genome sequencing identified recessive NAXD variants in each case. Variants were predicted to be potentially deleterious through in silico analysis. Reverse-transcription PCR confirmed altered splicing in one case. Subject fibroblasts showed highly elevated concentrations of the damaged cofactors S-NADHX, R-NADHX and cyclic NADHX. NADHX accumulation was abrogated by lentiviral transduction of subject cells with wild-type NAXD. Subject fibroblasts and muscle biopsies showed impaired mitochondrial function, higher sensitivity to metabolic stress in media containing galactose and azide, but not glucose, and decreased mitochondrial reactive oxygen species production. Recombinant NAXD protein harbouring two missense variants leading to the amino acid changes p.(Gly63Ser) and p.(Arg608Cys) were thermolabile and showed a decrease in Vmax and increase in KM for the ATP-dependent NADHX dehydratase activity. This is the first study to identify pathogenic variants in NAXD and to link deficient NADHX repair with mitochondrial dysfunction. The results show that NAXD deficiency can be classified as a metabolite repair disorder in which accumulation of damaged metabolites likely triggers devastating effects in tissues such as the brain and the heart, eventually leading to early childhood death.

Locus and allelic heterogeneity and phenotypic variability in Waardenburg syndrome.

Waardenburg syndrome (WS) is a disorder of neural crest cell migration characterized by auditory and pigmentary abnormalities. We investigated a cohort of 14 families (16 subjects) either by targeted sequencing or whole-exome sequencing. Thirteen of these families were clinically diagnosed with WS and one family with isolated non-syndromic hearing loss (NSHL). Intra-familial phenotypic variability and non-penetrance were observed in families diagnosed with WS1, WS2 and WS4 with pathogenic variants in PAX3, MITF and EDNRB, respectively. We observed gonosomal mosaicism for a variant in PAX3 in an asymptomatic father of two affected siblings. For the first time, we report a biallelic pathogenic variant in MITF in a subject with WS2 and a biallelic variant in EDNRB was noted in a subject with WS2. An individual with isolated NSHL carried a pathogenic variant in MITF. Blended phenotype of NSHL and albinism was observed in a subject clinically diagnosed to have WS2. A phenocopy of WS1 was observed in a subject with a reported pathogenic variant in GJB2, known to cause isolated NSHL. These novel and infrequently reported observations exemplify the allelic and genetic heterogeneity and show phenotypic diversity of WS.

Development and validation of a dried blood spot test for thiamine deficiency among infants by HPLC-fluorimetry.

Thiamine deficiency, if detected early in infancy, can be treated with thiamine supplementation and can prevent seizures, other disabilities and death. The dried blood spot (DBS) sampling technique is an attractive sample collection technique for infants. The present study reports the development and validation of a highly sensitive and precise method for quantification of thiamine diphosphate from DBS. The method utilizes full-spot analysis of a volumetrically deposited 40 µl DBS. The analyte was extracted from the DBS using 50% methanol and then derivatized using potassium ferricyanide to thiochrome. Separation was achieved with the help of an Inertsil ODS C18 column (5.0 µm, 250 × 4.6 mm) using 150 mm phosphate buffer pH 7-acetonitrile (90:10, % v/v) as the mobile phase. The use of a fluorimetric detector gave a good response to the thiochrome derivative offering good sensitivity for the method. The excitation and emission wavelengths were 367 and 435 nm, respectively. The limit of detection and lower limit of quantification were 5 and 10 ng/ml, respectively. Linearity was demonstrated from 10 to 1000 ng/ml, and precision (CV) was <12.08%, at all tested quality control levels. The method accuracy was 89.34-118.89% with recoveries >80%. Bland-Altman analysis of DBS sampling vs. whole blood demonstrated a mean bias of only 1.16 ng/ml, with a majority of the 60 investigated patient samples lying within 7.2% of the corresponding concentration measured in blood, thereby meeting the clinical desirable biological specification criterion and showing that the two methods are comparable.

Cost-Effective HPLC-UV Method for Quantification of Vitamin D2 and D3 in Dried Blood Spot: A Potential Adjunct to Newborn Screening for Prophylaxis of Intractable Paediatric Seizures.

25-Hydroxyvitamin D (25-(OH)D) deficiency is recently been described as one of the multiple factors responsible for pediatric seizures. 25-Hydroxyvitamin D3 and 25-Hydroxyvitamin D2 are the well-known markers to determine Vitamin D status. In this work we report the development of a sensitive and cost effective HPLC technique for the quantification of the vitamin D metabolites from dried blood spot samples (DBS). The metabolites were extracted using acetonitrile-methanol-0.1% formic acid (60 : 20 : 20 (v/v)) and analyzed on an Acclaim C18 column (150 × 4.6 mm i.d., 3 µm) at a flow rate of 1 mL/min. The method was linear in the range of 10-80 ng/mL. Limit of detection and limit of quantification (LOQ) of the method were 5 and 10 ng/mL respectively. Extensive stability studies demonstrated the analytes to be stable in stock and matrix with a percent change within the acceptable range of ±15%. Comparison of the newly developed HPLC-DBS method with the reported LC-MS-DBS and electrochemiluminescence immunoassay (ECLIA) methods followed by Bland-Altman analysis demonstrated a bias of 0.08 and -0.14, respectively proving the methods are comparable. Application of the developed method to a pediatric seizure cohort depicted 46.6% of cases as deficient and 26.6% as insufficient for 25-(OH)D. Among deficient cases 8 samples were below 10 ng/mL and exact amount was not calculated since these were below the LOQ levels. The mean ± standard deviation (S.D.) in the remaining 6 deficient cases was 13.22 ± 2.80 ng/mL. The levels in healthy infants were 33.9 ± 6.11 ng/mL. The method can be used routinely for assessing 25-(OH)D deficiency in newborn.

Randomized controlled trial on effectiveness of mHealth (mobile/smartphone) based Preterm Home Care Program on developmental outcomes of preterms: Study protocol.

AIM: To describe a randomized controlled trial protocol designed to evaluate the effectiveness of mobile health based Preterm Home Care Program (mHealthPHCP) known as "NeoRaksha" mobile health application in improving parent-infant-interaction, growth and development of preterms. DESIGN: A prospective, randomized controlled clinical trial. The protocol is approved and funded by Department of Biotechnology, Government of India on 2 August 2016. METHODS: A total of 300 preterm-mother dyads admitted to neonatal intensive care unit of a tertiary care hospital will be recruited and randomized to intervention and control group. The intervention group would receive mobile health based Preterm Home Care Program and the control group would receive standard preterm care. Intervention group will be followed up at home by community health workers known as Accredited Social Health Activist who will be trained in using the NeoRaksha mobile health application. Preterms outcomes will be assessed during follow-up at hospital. DISCUSSION: Supporting continuity of preterm care is vital as parents and preterms experience transition from Neonatal Intensive Care unit to their home. Empowering mothers and community health workers by integrating mobile technology into health care can help promote healthy preterms, enhance development outcomes and follow-up, which in turn can reduce the mortalities, morbidities, and disabilities associated with prematurity. IMPACT: The results of this study could open up new horizons in integrating hospital and home based preterm care through technology, which paves way to scale up the model across the countries.

Acute hemodynamic effects of methylxanthine therapy in preterm neonates: Effect of variations in subgroups.

BACKGROUND: Methylxanthines have cardiac stimulant effects. The current study aimed to compare acute hemodynamic changes between caffeine and aminophylline in ≤34 weeks' preterm neonates. METHODS: The study was performed using information on echocardiography measurements from preterm neonates recruited for apnea of prematurity (75 of 240) and preventing extubation failure (113 of 156) studies. The neonates were randomized either to the caffeine or aminophylline groups. Neonates with no maintenance followed by loading doses with both the methylxanthines (caffeine and aminophylline) and incomplete echocardiography examination were excluded. RESULTS: Cardiac parameters were found to be similar between groups. The heart rate was higher among the aminophylline-treated neonates (p < 0.001) than among the caffeine-treated ones. End-systolic volume was higher among both caffeine- (p < 0.001) and aminophylline-treated neonates (p = 0.001) when compared with pretreatment values. End-diastolic volume was statistically higher in both groups' neonates (p = 0.01). The odds of increase in cardiac output was higher; however, increase in ejection fraction was less in caffeine-treated small-for-gestation-age neonates. CONCLUSION: Caffeine has similar effects on cardiac parameters as aminophylline; however, caffeine-treated small-for-gestation stratification gave rise to significant cardiac variations.

Knowledge and attitude of parents/caregivers towards hearing loss and screening in newborns - a systematic review.

OBJECTIVE: The parents/caregivers of a newborn play a pivotal role in the process of hearing screening and intervention. The decisions taken by them depend on their knowledge and attitude. The purpose of this study was to review the literature systematically on knowledge and attitude of parents/caregivers towards infant hearing loss and newborn hearing screening. DESIGN: A systematic search was conducted using electronic databases for the periods from 1990 to March 2016. Two authors scrutinized the studies and extracted the data based on predetermined criteria. STUDY SAMPLE: Ten studies. RESULTS: Ear discharge was correctly identified as a risk factor for hearing loss along with measles, drugs/medication, family history, congenital causes and noise exposure. The studies revealed mixed results for knowledge about newborn hearing screening. Overall, the parents/caregivers showed positive attitudes towards hearing screening and intervention options. However, due to heterogeneity in the studies, it's hard to derive a conclusion. CONCLUSIONS: The present review sheds light on the common areas of misconception among parents/caregivers about risk factors of infant hearing loss and newborn hearing screening. The review also draws attention to the need to have more studies exploring this knowledge and attitude of parents/caregivers among diverse populations.

Clinical utility of fetal autopsy and its impact on genetic counseling.

OBJECTIVES: We aimed to analyze the utility of fetal autopsy in terms of its contribution to establishing a definitive diagnosis and its impact on genetic counseling. SUBJECTS AND METHODS: Detailed fetal autopsy was carried out in fetuses referred for examination. Clinical utility of fetal autopsy and its impact on counseling were measured by adapting previously published parameters. RESULTS: We performed autopsy in 230 fetuses. There were 106 cases with single system and 92 cases with multisystem involvement. We confirmed prenatal findings in 23% of cases and observed additional findings in 37% of cases. In 23% of cases, autopsy findings differed enough to change the diagnosis. However, in 17% of fetuses, no cause of fetal loss was determined. Risk of recurrence became clear in 30.3% of the fetuses, and risk remained the same, but the diagnosis was different in 4.8% of cases after autopsy. Hence, autopsy led to refinement of the risk of recurrence in 36% of cases. Autopsy aided prenatal counseling of couples in 77% of cases by either confirming the prenatal findings (35%) or providing new information/ruling out a diagnosis (42%). CONCLUSION: The present study quantifies the utility of fetal autopsy in reproductive genetic counseling in a large cohort.

Impairment of Venous Drainage on Extracorporeal Membrane Oxygenation Secondary to Air Trapping in Acute Asphyxial Asthma.

The inability to adequately support a patient on extracorporeal membrane oxygenation (ECMO) due to impaired drainage is not an uncommon occurrence during support. Typically, the causes include hypovolemia, kinks in the circuit, cannula malposition, or inadequate cannula size. In this report we present an uncommon etiology of this problem. A 3-year-old female presented to our hospital in status asthmaticus and pulseless electrical activity (PEA). This was a result of dynamic hyperinflation of the lungs causing physical obstruction of venous return to the heart. Upon initiating venoarterial (VA) ECMO, we experienced inadequate drainage that did not improve despite multiple interventions. This resolved with the addition of an inhaled anesthetic gas to treat this patient's severe bronchospasm. This case illustrates the importance of considering a patient's physiology or disease state and how that may affect the mechanics of ECMO support.

Evidence that the insertion events of IS2 transposition are biased towards abrupt compositional shifts in target DNA and modulated by a diverse set of culture parameters.

Insertion specificity of mobile genetic elements is a rather complex aspect of DNA transposition, which, despite much progress towards its elucidation, still remains incompletely understood. We report here the results of a meta-analysis of IS2 target sites from genomic, phage, and plasmid DNA and find that newly acquired IS2 elements are consistently inserted around abrupt DNA compositional shifts, particularly in the form of switch sites of GC skew. The results presented in this study not only corroborate our previous observations that both the insertion sequence (IS) minicircle junction and target region adopt intrinsically bent conformations in IS2, but most interestingly, extend this requirement to other families of IS elements. Using this information, we were able to pinpoint regions with high propensity for transposition and to predict and detect, de novo, a novel IS2 insertion event in the 3' region of the gfp gene of a reporter plasmid. We also found that during amplification of this plasmid, process parameters such as scale, culture growth phase, and medium composition exacerbate IS2 transposition, leading to contamination levels with potentially detrimental clinical effects. Overall, our findings provide new insights into the role of target DNA structure in the mechanism of transposition of IS elements and extend our understanding of how culture conditions are a relevant factor in the induction of genetic instability.

A comprehensive approach for detection of biotin deficiency from dried blood spot samples using liquid chromatography-mass spectrometry.

Aim: The aim of the present study is to develop a liquid chromatography-mass spectrometry method to measure two important biomarkers of biotin deficiency from dried blood spot samples for effective management of the disorder. Materials & methods: The method was developed on a liquid chromatography-mass spectrometry system using pentafluorophenyl column employing a mobile phase composition of methanol and water in the isocratic mode. A full validation of the method was performed as per relevant guidelines. Results & conclusion: Correlation between the results of dried blood spot and plasma method was evaluated to determine the interconvertibility of the method. The developed method was successfully applied for establishing the reference ranges for these biomarkers in the population of Udupi, a coastal district of South India.

Biotin deficiency can lead to many complications such as impaired growth, compromised immune function, depression, myalgia and may even lead to death. The disorder can be managed by supplementation of biotin. Early detection is crucial in managing biotin deficiency. In this paper we describe a comprehensive method for the early detection of biotin deficiency. The method employs the use of minimally invasive blood sampling such as dried blood spot that is suitable for vulnerable neonatal population.