High Risk Stratified Neonatal Screening

Transcription

1 The Indian Journal of Pediatrics ORIGINAL ARTICLE High Risk Stratified Neonatal Screening ICMR Task Force on Inherited Metabolic Disorders Received: 8 June 2017 /Accepted: 16 November 2017 # Dr. K C Chaudhuri Foundation 2018 Abstract Objectives To ascertain the proportion of neonates and infants presenting with suspicion of an inborn error of metabolism in the centers identified by ICMR for newborn screening. Methods A set of red flag signs suggestive IEM were listed by the Taskforce members. The age group was limited to one year as it was understood that most of the small molecules with a severe phenotype would present before the age of one year. Further investigations were tandem mass spectrometry, gas chromatography mass spectrometry and high performance liquid chromatography. Results A total of 851 babies with an index of suspicion were investigated using a combination of these modalities. The yield from this sample was 31.7%, better than reported in literature owing to a more specific inclusion criteria. Methylmalonic acidemia followed by Propionic acidemia were the most common organic acidemias, while maple syrup urine disease and classic citrullinemia were the common aminoacidopathies. Conclusions If all the sick care neonatal unit patients would undergo high risk stratified screening, the likely benefit of the high end technologies currently available in India would become apparent. Though this is not the opportune moment to start the expanded screening program in the country, none of the neonates admitted for any of these errors should be bereft of the diagnosis. This has implications not only for the index case but for its impact on the family s reproductive decisions. The Task Force consitituted by the Indian Council of Medical Research definitely feels that the high risk expanded screening program should be implemented for the sick newborns getting admitted in the Neonatal Intensive Care Units or the Sick Care Newborn Units. Keywords Inborn metabolic errors. Sick care newborn units. High risk screening. India Introduction Newborn screening as a National Health Program is yet to see light in India. Expanded newborn screening is even more unlikely to see the horizon. On the other hand, stratified or high-risk Members of the ICMR Task Force contributed equally to the study (names arranged in an alphabetical order): Dr. Rita Christopher, NIMHANS, Bangalore, India; Dr. A. Radha Rama Devi, Rainbow Children Hospital & Sandor Life Sciences, Road No 3, Banjara Hills, Hyderabad, India; Dr. Neerja Gupta, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India; Dr. Madhulika Kabra, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India; Dr. Seema Kapoor, Maulana Azad Medical College, New Delhi , India; Dr. Roli Mathur, Indian Council of Medical Research, New Delhi, India; Dr. Mamta Muranjan, KEM Hospital, Mumbai, India; Dr. Puneet K. Nigam, Vimta Laboratories, Hyderabad, India; Dr. R. M. Pandey, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India; Dr. Arun Singh, IPGMER, Kolkata, India; Dr. S. Suresh, MEDISCAN, Chennai, India * ICMR Task Force on Inherited Metabolic Disorders drseemakapoor@gmail.com screening akin to a targeted diagnosis exists in India and is important for the family in question. Though treatment is yet not universally available, diagnosis can enable genetic and prenatal counselling to prevent the family from another catastrophic situation. While embarking on screening for congenital hypothyroidism and congenital adrenal hyperplasia, the Task Force constituted by the Indian Council of Medical Research, decided to include high risk screening in cases suspected to have an inborn error of metabolism. Tandem Mass Spectrometry (TMS), Gas Chromatography Mass Spectrometry (GCMS) and High Performance Liquid Chromatography (HPLC) were identified as the modalities of testing. This communiqué presents the results of high risk screening using these modalities from 5 cities across the country. The aim of the Task Force was also to support both technical expertize and capacity building in the field of inborn metabolic errors. The suspicion to include the cases was constituted by a group of signs and symptoms to ensure maximal yield. A debate on the age of inclusion finally prompted the Task Force

2 to choose one year as the age as most of Inborn Errors of Metabolism (IEMs) with a severe manifestation would have presented in the neonatal period and some may extend to infancy. The signs and symptoms constituted the symptom complex agreed upon. Symptomatic newborns with pointers on clinical examination and general signs like lethargy, persistent vomiting, seizures, floppiness, unusual body odor, urine odor and failure to thrive were included. Tachypnea, jaundice, skin and hair changes were additional contributors enhancing suspicion. Significant laboratory pointers were hypoglycemia, intractable metabolic acidosis and unexpected metabolic alkalosis. An asymptomatic sibling in a case where sibling death was thought of because of a metabolic error also warranted inclusion. The exclusion criteria were infants with culture positive sepsis with biochemical derangements not explainable on the basis of sepsis alone without a contributory family history. The diagnosis of hypoxic ischemic encephalopathy (HIE) with a confirmed cord blood ph, suggestive non-stress test and observed APGAR values was made and these neonates were excluded. In infants and children all the above symptomatology was considered. Specific situations in the infants were intermittent episodes of altered sensorium, recurrent unexplained vomiting with sensorial changes responding to restriction of feeds, intermittent movement disorders and the label of cerebral palsy without perinatal difficulties. Unexplained cardiomyopathy and progressive developmental delay were also considered strong indicators. Material and Methods All neonates and infants fulfilling the criteria were enrolled at each center. A clinical case record performa and an informed consent form translated into the vernacular language were administered to each parent. Initial biochemical investigations available with the patient including neuroimaging findings were reviewed by the treating clinician and recorded. An effort was made to perform serum ammonia and plasma lactate, wherever possible. An arterial blood gas was done to confirm anion gap, wherever feasible. In all patients, blood was collected on a 903 S & S GE Whatman filter paper and air dried for 2 3 h and transported to National Institute of Mental Health And Neurosciences, Bangalore and in few instances to Biochemical Genetics laboratory at Maulana Azad Medical College. Gas chromatography was done at Sandor laboratories on samples of either early morning 20 ml liquid urine or dried filter paper sample collected on Whatmann 3 filter paper on the Shimadzu platform using the metabolite library of NIST and the one supplied by the vendor. Samples for high performance liquid chromatography were collected in a pretreated sulfosalicylic acid vial. High Performance Liquid Chromatography was done at Maulana Azad Medical College utilizing post column derivatization method using ninhydrin at an Agilent Platform. Tandem Mass spectrometry was performed on a Waters TQ D system using Perkin Elmer s Neobase kit employing a derivitization method. For Quality assurance aspect, the laboratory was enrolled in the CDC Atlanta QA program. Gas chromatography was performed. The initial screening technology used was LCMSMS and confirmatory platforms used were GCMS and HPLC. Mutation analysis of specific gene was done wherever it was feasible. The data obtained was collated at the Central collection unit at AIIMS in the Department of Biostatistics. Results Neonates and infants enrolled at all the centers were 851. Table 1 depicts the number of infants subjected to various tests from these centers. The commomest organic acidemia was methylmalonic acidemia (26%) followed by propionic acidemia (13%). Glutaric aciduria was easy to suspect based on radiological clues and was an important organic acidemia. Figure 1 demonstrates the spectrum of organic acidemias detected in the study. Amongst the group of amino acid disorders, the commonest was maple syrup urine disease (33%) followed by tyrosinemia and citrullinemia. Figure 2 demonstrates the amino acid disorders detected. Table 2 depicts the different patients from collaborating centers with a diagnosis of an inborn error of metabolism. In the subgroup of fatty acid disorders one case was suspected on the basis of hypoketotic hypoglycemia and one case of carnitine palmitoyl transferase 1 deficiency was confirmed by molecular means. No case of medium chain acyl coa dehydrogenase deficiency was detected. Discussion Expanded screening for potentially treatable metabolic disorders is common place in most developed nations. Important reasons for their under recognition in our country are consideration for the rarity, unavailability of high end technologies for diagnosis, limited resources for molecular confirmation and a limited plethora of presentation blanketed as sepsis. The Task Force constituted by the Indian Council of Medical Research at that point did not debate on the inclusion of expanded screening in the program. There were obvious reasons for this. There was paucity of data regarding epidemiology of these disorders, currently special medical foods for this category were not available and even more the emergency drugs for the management of these sick newborns were also not always available. The Task Force however did not want to

3 Table 1 Samples contributed by each participating center Chennai Kolkata Mumbai Delhi Hyderabad No. of samples collected from the suspected cases with an inborn metabolic error No. of Screen positive cases on initial screening No. of TMS & GCMS* performed (*includes more than 1 sample per patient) No. of HPLC performed No. of confirmed positive cases TMS Tandem mass spectrometry; GCMS Gas chromatography mass spectrometry; HPLC High performance liquid chromatography lose this strategic time point, as capacity and infrastructure building were important in order to envisage an expanded program later. As a trade off, it was decided to start a program, which looked at the diagnostic confirmation of infants with red flag signs, and this was designated as high-risk screening. The age group was limited to one year as it was discussed that most of these small molecule IEMs with a severe phenotype would present before the age of one year. The possibility of missing the late onset intermittent presentations was understood but not included due to limited resources. The data, which has emerged, appears encouraging to the group dedicated to Genomics and Genetics. The yield of 31.7% demonstrates that in these an index of suspicion had been entertained and making a diagnosis benefited the family in question. The group of organic acidemia was a formidable group and followed closely by the disorders of amino acid metabolism. A review of data from India reveals three different subgroups where IEMs have been reported. The earliest report on possible metabolic etiology was in 1991, in a review conducted by the ICMR collaborating center on a multicentric study on the genetic causes of mental retardation [1]. Metabolic etiology was suspected in 5% cases, of the 1314 children studied. In this study the cause of mental retardation could not be identified in 66.5% cases. The authors admitted that a part of this subgroup had a positive screening test but further tests to delineate the etiology were not available. Bhatt Fig. 1 The spectrum of organic acidemias in the profile of patients across all centers. GA Glutaric aciduria; HMG CoA Hydroxymethyl glutaryl coenzyme A; MMA Methylmalonic acidemia; PPA Propionic acidemia et al. reported mucopolysaccharidosis, lysosomal storage disorders, Wilsons and galactosemia to be common causes [2], where autosomal recessive conditions mainly metabolic cause was detected in 48 cases of mental handicap (2%). In their study they described one case each of phenylketonuria, alkaptonuria and tyrosinemia and the authors also described 3 cases of congenital hypothyroidism. Another group evaluated the aminoacid disorders in children with mental handicap only. Forty-one (0.9%) cases were detected with amino acid disorders among 4500 children surveyed. They reported amino acid disorders of rare occurrence such as dicarboxylic aminoaciduria, hydroxykynureninuria, persistent hypertyrosinemia, hydroxyprolinemia, hypervalinemia, and also described a new metabolic defect, threoninemia. They observed a preponderance of males with amino acid disorders and parental consanguinity was present in 54% of cases with amino acid disorders [3]. Another study, again on the subgroup of 1314 children in a multicentric study by ICMR, deduced that metabolic defects constituted 5% of causes. Plausibly high-end technology to detect a host of metabolic etiologies did not exist at that time to pick up a host of metabolic abnormalities which can be detected now [4]. In a series of 101 cases reported by Jain et al., a total of 14 cases were due to a metabolic cause. Four were due to disorders like pyruvate dehydrogenase deficiency, malonic aciduria, homocystinuria and free carnitine deficiency. The other common causes were mucopolysaccharidosis, Organic acidemia spectrum PPA MMA GA type1 GA type 2 Mul ple Carboxylase Methylglutaconic aciduria Dicarboxylic aciduria Isovaleric acidemia HMG CoA Unclassified

4 Fig. 2 The amino acid and urea cycle disorders across the centers. MSUD Maple syrup urine disease; NKH Non ketotic hyperglycinemia; OTC Ornithine transcarbamylase; PKU Phenylketonuria Amino acid & Urea cycle defects MSUD Citrullinemia PKU Tyrosinemia NKH OTC def Argininemia Arginosuccinic aciduria Unclassified Gaucher disease and Canavans disease [5]. In a study by Tikaria et al., the metabolic etiology as a cause of developmental delay was found in 5% of cases [6]. In another subset, a group suspected with high probability of IEM, had a high yield as reported by Narayanan et al. [7]. Of the 869 cases evaluated, 40.2% were less than one year of age. One case each of non ketotic hyperglycinemia, maple syrup urine disease, beta ketothiolase deficiency, ornitinine transcarbamylase deficiency and 3 HMG CoA lyase deficiency were detected. Two cases each of propionic acidemia and methylmalonic acidemia were reported. However, they reported 7 cases of carnitine deficiency. Nagaraja et al. reported a Table 2 Number of patients reported with a diagnosis of an inborn error of metabolism from the centers Total number screened Amino acid disorders Organic acidemias Fatty acid oxidation defects Others Kolkata N =125 Mumbai N =191 Hyderabad N =242 Chennai Center N =118 Delhi Center N =175 N = 3, MSUD Arginosuccinic aciduria Argininemia-1 Citrullinemia-1 MSUD-1 PKU-2 Hyperphenylalaninemia-1 MSUD-4 NKH-2 MSUD-3 UCD-1 Suspected UCD-2 Urea Cycle Defects OTC Def-1, Citrullinemia-2 MSUD-5 PKU-1 PPA = 2 GA type 1 = 2 MMA = 2 Unclassified organic aciduria = 6 PPA- 1 MMA- 2 Beta ketothiolase-1 Glutaric aciduria type 1 2 MMA-8 GA- Type 1 7 PPA-7 IVA-3 BKT-3 3- MCG-2 3- MG-1 GA type II-2 DCA-1 MMA-2 IVA-1 MMA-10, GA-8, Beta ketothiolase def -4, HMG CoA lyase-2, PPA-2 GAII- four, Multiple Carboxylase def-1, Unclassified- 5 Suspected FAOD-1 CPTI-1 Pompe- 2 Mitochondrial-1 Canavan-1 Neonatal diabetes-1 Biotinidase-1 Mitochondrial-2 Zellweger-1 CDG-1 BKT Beta ketothiolase deficiency; CDG Congenital disorder of glycosylation; DCA Dicarboxylic aciduria; FAOD Fatty acid oxidation defect; GA Glutaric aciduria; HMG Hydroxymethyl glutaryl; IVA Isovaleric acidemia; MCG Methyl crotonyl glycinuria; MMA Methylmalonic acidemia; MSUD Maple syrup urine disease; NKH Nonketotic hyperglycinemia; OTC Ornithine transcarbamylase; PKU Phenylketonuria; PPA Propionic acidemia; UCD Urea cycle defect

5 yield of 3.2% amongst cases referred to them with a high probability of IEM. They reported that the amino acid metabolism disorders constituted 54% of the cases, organic acidemias constituted 41.6% while the least common were fatty acid disorders which were found in only 4.4% of cases [8]. This study is similar to the present study in the subgroup enlisted and age group covered. The present study also had a very small group of fatty acid oxidation disorders, as the medium chain acyl CoA dehydrogenase would have most likely been missed. This is in striking contrast to the prospective study reported by the Heel to Heal program, a program under the Goa Government. The maximum group of patients screened from the cohort was the fatty acid group. They reported a yield of 0.28% from a cohort of 27,578 patients. The commonest were fatty acid oxidation disorders; of which 57 were fatty acid oxidation disorders, VLCAD constituting the diagnosis in 34 patients. The second most common were amino acid disorders, of which there were 3 cases of tyrosinemia and 2 cases of MSUD. Organic acid disorders were found in 12 cases of which methylmalonic/propionic constituted the maximum, being a total of 8 cases [9]. The communiqué thus highlights the significant presence of inborn errors of metabolism in India as depicted by various studies. If all the sick care neonatal unit patients would undergo high risk stratified screening, the likely benefit of the high end technologies currently available in India would become apparent. Though this is not the opportune moment to start the expanded screening program in the country, none of the neonates admitted for any of these errors should be bereft of the diagnosis. This has implications not only for the index case but for its impact on the family s reproductive decisions. The Task Force definitely feels that the high risk expanded screening program should be implemented for the sickest newborns getting admitted in the neonatal intensive care units or the sick care. Acknowledgements Writing Group: Dr. Seema Kapoor, Dr. Madhulika Kabra, Dr. Neerja Gupta. Steering Group: Late Dr. SS Aggarwal (Chairperson), Dr. I. C. Verma, Dr. Veena Kalra, Dr. Vasantha Muthuswamy and Dr. Vijay Kumar. Co-Investigators: AIIMS, New Delhi: Dr. Vinod Paul, Dr. Ashok Deorari, Dr. Sheffali Gulati, Dr. Ramesh Agarwal, Dr. Vandana Jain, Dr. Suman Vashishst, Dr. Suneeta Mittal; MAMC, Delhi: Dr. AP Dubey, Dr. Siddharth Ramji, Dr. Sangeeta Yadav, Dr. Swaraj Batra, Dr. Sangeeta Gupta; KEM Hospital, Mumbai: Dr. Keya Lahiri, Dr. Ruchi Nanavati; MEDISCAN, Chennai: Dr. Sujatha Jagadeesh, Dr. Sudha Rathna Prabhu, Dr. K Saraswathi, Dr. Rathna Kumari; IPGMER, Kolkata: Dr. Mitali Chatterjee, Dr. S. C. Biswas, Dr. Indranil Chakraborty, Dr. Tapas Som, Meena Jaishankar, Dr. Satinath Mukhopadhyay; Sandor, Hyderabad: Dr. A. I. Dherai and Dr. Srimannarayana Rao; NIMHANS, Bangalore: Dr.D.Nagaraja. Special Thanks to Mrs. Esha Chopra, Dr. Pallavi Vats, Dr. Pallavi, Mr. Amit Juneja, Dr. Neerja Gupta, Dr. Sudha Ratna Prabhu, all staff in the project for its execution. Indebted to: Late Dr. Taranath Shetty, NIMHANS, Bangalore and Late Dr. Suman Vashisht from AIIMS, New Delhi. Contributions ARRD, MK, SK, MM, AS, SS: Regional centres collected, analyzed the data and participated in patient care; RMP: Data coordination of the study; RM: Overall coordination of the study; PKN: Quality assurance; RC: Laboratory tests; SK, MK, RM, KM, RMP: Wrote the manuscript. SK and MM will act as guarantors of the paper. Compliance with Ethical Standards Conflict of Interest Source of Funding References None. Indian Council of Medical Research. 1. Rao BS, Subhash MN, Narayanan HS. Metabolic anomalies detected during a systematic biochemical screening of mentally retarded cases. Indian J Med Res. 1977;65: Bhatt C, Misra Z, Goyel N. Detection of inherited metabolic diseases in children with mental handicap. Indian J Clin Biochem. 2008;23: Swarna M, Jyothy A, Usha Rani P, Reddy PP. Amino acid disorders in mental retardation: a two-decade study from Andhra Pradesh. Biochem Genet. 2004;42: Multicentric study on genetic causes of mental retardation in India. ICMR Collaborating Centres & Central Co-ordinating Unit. Indian J Med Res. 1991;94: Jain S, Chowdhury V, Juneja M, et al. Intellectual disability in Indian children: experience with a stratified approach for etiological diagnosis. Indian Pediatr. 2013;50: Tikaria A, Kabra M, Gupta N, et al. Aetiology of global developmental delay in young children: experience from a tertiary care centre in India. Natl Med J India. 2010;23: Narayanan MP, Kannan V, Vinayan KP, Vasudevan DM. Diagnosis of major organic acidurias in children: two years experience at a tertiary care centre. Indian J Clin Biochem. 2011;26: Nagaraja D, Mamatha SN, De T, Christopher R. Screening for inborn errors of metabolism using automated electrospray tandem mass spectrometry: study in high-risk Indian population. Clin Biochem. 2010;43: Heel to heal. Government of Goa. The Goa Newborn Screening Program 3 Year Review Available at: dhsgoa.gov.in/documents/new_born.pdf. Accessed 24 May 2017.