Selective screening for organic acidurias and amino acidopathies in Pakistani children

Objective: To determine the frequency of organic acidurais (OA) and amino acidopathies (AA) in selected high-risk patients screened in two years.Study Design: Retrospective Observational study.Place and Duration of Study: The Aga Khan University Hospital (AKUH), Karachi, from January 2013 to December 2014.Methodology: Patients with OA and AA were included in the study and patients with IMDs other than OA and AA were excluded. Amino acids and organic acids were analyzed on high performance liquid chromatography and gas chromatography-mass spectrometry respectively. Clinical data and chromatograms of patients screened for IMDs were reviewed by chemical pathologist and metabolic physician.Results: Eighty-eight cases (4.7%) were diagnosed including 41 OA (46.5%), 28 AA (31.8%) and 19 others (21.5%) from 1,866 specimens analyzed. Median age of the patients was 1.1 years, with high consanguinity rate (64.8%). Among OA, methyl CoA mutase deficiency was diagnosed in 9 (10.2%) and was suspected in 2 (2.3%) cases. Five (5.7%) cases of MHBD (2-methyl-3-hydroxybutyryl-CoA), 4 (4.5%) each of PPA (propionic aciduria) and HMG-CoA lyase deficiency, 3 (3.4%) cases each of IVA (isovaleric aciduria), multiple carboxylase deficiency, fructose-1, 6-biphosphatase deficiency, fumarase deficiency, GA-1 (glutaric aciduria type 1) and 2 (2.3%) cases of EMA (ethyl-malonic aciduria). AA included 8 (9.1%) cases of MSUD (maple syrup urine disease), 6 (6.8%) cases of CBS (cystathionine beta-synthetase) and UCDs (urea cycle disorders) each, 5 (5.7%) cases of hyperphenylalaninemia and 3 (3.4%) cases of hyperprolinemia were reported. Other inherited metabolic disorders included: 9 (10.2%) cases of intracellular cobalamin defects, 2 (2.3%) cases each of alkaptonuria, Canavan\u27s disease, SUCL (succinate CoA ligase) deficiency, and 1 (1.1%) case each of DPD (dihydropyrimidine) deficiency, GA-2, NKH (non-ketotic hyperglycinemia), AADC (aromatic amino acid decarboxylase) deficiency.Conclusion: This study presents frequency of OA and AA in the high-risk Pakistani pediatric population analyzed locally

Diagnostic dilemma of patients with methylmalonic aciduria: Experience from a tertiary care centre in Pakistan

Objective: To determine the frequency of disorders leading to methylmalonic acidurias. Methods: This cross-sectional study was conducted from January 2013 to April 2016 at the Aga Khan University Hospital, Karachi, and comprised patients diagnosed with methylmalonic acidurias based on urine organic acid analysis. Clinical history and biochemical data was collected from the biochemical genetics laboratory requisition forms. Organic acid chromatograms of all the subjects were critically reviewed by a biochemical pathologist and a metabolic physician. For assessing the clinical outcome, medical charts of the patients were reviewed. SPSS 19 was used for data analysis. Results: Of the 1,778 patients 50(2.81%) were detected with methylmalonic acidurias. After excluding patients with non-significant peaks of methylmalonic acidemia, 41(2.31%) were included in the final analysis. Of these, 20(48.7%) were females, while the overall median age was 11.5 months (interquartile range: 6-41.5). On stratification by type of disorders leading to methylmalonic acidurias, 9(22%) had methylmalonic acidemia, 12(29%) had Cobalamin-related remethylation disorders, nonspecific methylmalonic acidurias in 16(39%), while 2(5%) each had succinyl coenzyme A synthetase and Vitamin B12 deficiency. respectively. Conclusion: Screening tests, including urine organic acid, provided valuable clues to the aetiology of methylmalonic acidurias

Enhancing specimen collection skills for dried blood spots through an immersive virtual learning environment: A cross-sectional study

Objective: The quality of dried blood spot (DBS) specimens impacts newborn screening (NBS) results, hence proper training is crucial for DBS specimen collection. To address this, a training module for Allied Health Professionals (AHPs) and nurses was created on Moodle, a virtual learning environment (VLE). The purpose of this research was to determine the feasibility and effectiveness of this module.Methodology: Participants were trained on-site (March to December 2019), through online training sessions (January to June 2020), and the two training strategies were compared. Data analysis included the total number of participants, cost-effectiveness, trainer engagement, and the number of unacceptable samples collected by nurses/AHPs trained by the two strategies.Results: A total of 55 nurses/AHPs were trained on-site, while 79 nurses/AHPs completed the online module and received certificates through online VLE-based training. The trainer engagement and cost were more for onsite training. After online training, the specimen rejection rate was reduced from 0.84% (44 rejected out of 5220 total specimens collected) to 0.38% (15/3920).Conclusions: This study shows that using VLE-based DBS specimen collection training is feasible and effective for training nurses and AHPs

Musculoskeletal manifestations in alkaptonuria: A cross-sectional study

This study aimed to determine the patient characteristics and clinical presentation of Alkaptonuria cases reported by the Biochemical Genetics Lab.An observational study was conducted at the Biochemical Genetics Lab. Alkaptonuria patients were diagnosed based on the homogentisic acid peak in urine and their demographics and clinical data collected from to 2013 to 2019. Clinical history related to joint diseases, ochronotic presentation, and urine darkening on standing was collected.During 7 years, 21 Alkaptonuria cases were reported from BGL; mean age 19.4 ± 24.5 years (range 0.2-66 years) and male to female ratio of 2:1. Of the total, only 9 were adults (mean age, 44 ± 12 years). Most adult patients had musculoskeletal involvement, with joint pain (n = 9) and ochronotic pigmentation (n = 6), whereas all patients presented with a history of urine darkening on standing (21/21 cases).The high prevalence of musculoskeletal involvement observed in patients with albuminuria is likely to be missed by physicians unless specifically tested for in such cases

Application of Sigma Metrics for the Assessment of Quality Assurance for Plasma Amino Acid Analysis in Biochemical Genetics Laboratory in Pakistan

Background: Quality is assessed on sigma scale with 3 sigma as the minimum allowable sigma and 6 being world-class quality goal. We aim to present sigma-metrics of plasma amino acids (AA) observed in our Biochemical Genetics Laboratory (BGL). Methods: Internal quality control (IQC) data of AA run in BGL was analyzed from 2013 -2014. Two years mean from IQC and proficiency testing (PT) results were utilized to establish coefficient of variation (CV) and bias respectively. Bias (%): (mean of all laboratories using same instrument-BGL AKU mean)/(mean of all laboratories using same instrument)*100. Sigma metrics were then calculated: ∑(σ)= (total allowable error – bias%)/CV. Results: Overall CV of individual AA ranged from 3.46-11.2%. The laboratory mean and PT target mean showed6. Plasma asparginine, histidine, glutamine and aspartate elicited \u3c 3 on sigma-scale. We achieved sigma metrics of the range 3.1–5.9 for remaining amino acids. Of all the amino acids evaluated the average sigma level was 4.8. Conclusion: Satisfactory sigma metrics were achieved for all AA. The AA below3 sigma must be evaluated with discretion and strict quality control checks. Work Done By Section of Chemical Pathology, Departments of Pathology and Laboratory Medicine and Pediatrics and Child Health*, Aga Khan University Hospital (AKUH

Evaluating laboratory performance in external quality assessment schemes for urine organic acids by GCMS

Background: Biochemical genetics laboratory (BGL) differs from clinical chemistry laboratory in interpretation that is necessary to make its results meaningful. Aim: To evaluate the performance of BGL for analysis/interpretation of urinary organic acid (UOA) through external proficiency testing. Materials and Methods: BGL started participation in ERNDRIM since 2013 (18 samples from 3 surveys)and College of American Pathologist (CAP)(4 samples from 2 surveys) in 2014.Scoring/sample in ERNDRIMis on analytical and interpretative performance and recommendations for further testing (maximum score 4). Results: In ERNDIM, satisfactory diagnosis (score 4) was provided for 3-methyl crotonyl CoA-carboxylase enzyme deficiency, IVA, MMA, malonicacidurias, GAII, 3-MGA, L-Dopa agonist treatment, hyperphenylalaninemia, GAI and II, PPA and PKU. In a sample scored 3, majority participants were unable to associate a metabolite with diagnosis but weren’t penalized indicating educational role of ERNDRIM. Two samples misdiagnosed the disease. In one diagnosis of MSUD was missed due to mild excretion of metabolites and in another orotic acid peak wasn’t determined by GCMS. Both the samples were challenging and posed difficulties for laboratories. In CAP, GA I, neuroblastoma, PPA and PKU were correctly identified. Conclusion: Evaluation by CAP and ENDRIM has allowed BGL to monitor its performance and intensify their insight. Conducted by the Section of Chemical Pathology, Dept. of Pathology and Laboratory Medicine and Dept. of Pediatrics and Child Health*, Aga Khan University Hospital (AKUH). Pakista