A compound heterozygote case of glutaric aciduria type II in a patient carrying a novel candidate variant in ETFDH gene: A case report and literature review on compound heterozygote cases.

BACKGROUND: Glutaric aciduria type II (GA2) is a rare genetic disorder inherited in an autosomal recessive manner. Double dosage mutations in GA2 corresponding genes, ETFDH, ETFA, and ETFB, lead to defects in the catabolism of fatty acids, and amino acids lead to broad-spectrum phenotypes, including muscle weakness, developmental delay, and seizures. product of these three genes have crucial role in transferring electrons to the electron transport chain (ETC), but are not directly involve in ETC complexes. METHODS: Here, by using exome sequencing, the cause of periodic cryptic gastrointestinal complications in a 19-year-old girl was resolved after years of diagnostic odyssey. Protein modeling for the novel variant served as another line of validation for it. RESULTS: Exome Sequencing (ES) identified two variants in ETFDH: ETFDH:c.926T>G and ETFDH:c.1141G>C. These variants are likely contributing to the crisis in this case. To the best of our knowledge at the time of writing this manuscript, variant ETFDH:c.926T>G is reported here for the first time. Clinical manifestations of the case and pathological analysis are in consistent with molecular findings. Protein modeling provided another line of evidence proving the pathogenicity of the novel variant. ETFDH:c.926T>G is reported here for the first time in relation to the causation GA2. CONCLUSION: Given the milder symptoms in this case, a review of GA2 cases caused by compound heterozygous mutations was conducted, highlighting the range of symptoms observed in these patients, from mild fatigue to more severe outcomes. The results underscore the importance of comprehensive genetic analysis in elucidating the spectrum of clinical presentations in GA2 and guiding personalized treatment strategies.

[Analysis of clinical features and genetic variants in three children with late-onset Multiple acyl-Coenzyme A dehydrogenase deficiency].

OBJECTIVE: To explore the clinical characteristics and genetic variants in three children with late-onset Multiple acyl-Coenzyme A dehydrogenase deficiency (MADD type Ⅲ). METHODS: Clinical data of three children diagnosed with late-onset MADD at the Children's Hospital Affiliated to Zhengzhou University between March 2020 and March 2022 were retrospectively analyzed. All children were subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. All children had received improved metabolic therapy and followed up for 1 ~ 3 years. RESULTS: The children had included 2 males and 1 female, and aged from 2 months to 11 years and 7 months. Child 1 had intermittent vomiting, child 2 had weakness in lower limbs, while child 3 had no symptom except abnormal neonatal screening. Tandem mass spectrometry of the three children showed elevation of multiple acylcarnitines with short, medium and long chains. Children 1 and 2 showed increased glutaric acid and multiple dicarboxylic acids by urine Gas chromatography-mass spectrometry (GC-MS) analysis. All children were found to harbor compound heterozygous variants of the ETFDH gene, including a paternal c.1211T>C (p.M404T) and a maternal c.488-22T>G variant in child 1, a paternal c.1717C>T (p.Q573X) and a maternal c.250G>A (p.A84T) variant in child 2, and a paternal c.1285+1G>A and maternal c.629A>G (p.S210N) variant in child 3. As for the treatment, high-dose vitamin B2, levocarnitine and coenzyme Q10 were given to improve the metabolism, in addition with a low fat, hypoproteinic and high carbohydrate diet. All children showed a stable condition with normal growth and development during the follow-up. CONCLUSION: The compound heterozygous variants of the ETFDH gene probably underlay the muscle weakness, remittent vomiting, elevated short, medium, and long chain acylcarnitine, as well as elevated glutaric acid and various dicarboxylic acids in the three children with type Ⅲ MADD.

Sensory neuropathy as a manifestation of multiple acyl-coenzyme A dehydrogenase deficiency.

Multiple acyl-coenzyme A dehydrogenase deficiency (MADD) is a rare metabolic disorder which typically manifests with muscle weakness. However, despite late-onset MADD being treatable, it is often misdiagnosed, due in part to the heterogeneity of presentations. We report a case of late-onset MADD manifesting first as a sensory neuropathy before progressing to myopathic symptoms and acute metabolic decompensation. Early diagnostic workup with acylcarnitine profiling and organic acid analysis was critical in patient outcome; metabolic decompensation and myopathic symptoms were completely reversed with riboflavin supplementation and dietary modification, although sensory neuropathy persisted. Clinical consideration of MADD as part of the differential diagnosis of neuropathy with myopathy is crucial for a timely diagnosis and treatment of MADD.

The presence of white cell Jordan's anomaly in multiple Acyl-CoA dehydrogenase deficiency: A case report and implications for clinical practice.

BACKGROUND: Multiple Acyl-CoA Dehydrogenase Deficiency (MADD), also known as Glutaric Aciduria Type II, is an exceptionally rare autosomal recessive genetic disorder that disrupts the metabolism of fatty acids, amino acids, and choline. It presents with a wide range of clinical manifestations, from severe neonatal-onset forms to milder late-onset cases, with symptoms including metabolic disturbances and muscle weakness. Jordan's anomaly is a distinctive morphological feature found in peripheral blood white cells and is typically associated with Neutral Lipid Storage Disease (NLSD). CASE REPORT: In our case report, the patient initially presented with symptoms of vomiting, abdominal pain, and altered consciousness. The presence of white cell Jordan's anomaly was detected in the blood smear. Subsequent serum tests revealed elevated levels of transaminases, creatine kinase, uric acid, and multiple acylcarnitines, while blood glucose and free carnitine levels were notably reduced. High-throughput sequencing confirmed heterozygous pathogenic variants in the electron-transferring flavoprotein dehydrogenase (ETFDH) gene, leading to the conclusive diagnosis of MADD. Following a three-month treatment regimen involving high-dose vitamin B2, coenzyme Q10, and other supportive interventions, the patient exhibited significant clinical improvement, ultimately resulting in discharge. CONCLUSION: The identification of Jordan's anomaly in a pediatric patient with late-onset MADD sheds light on its broader implications within the realm of lipid storage myopathies. The significance of this finding extends beyond its conventional association with NLSD, challenging the notion of its exclusivity. This novel observation serves as a compelling reminder of the diagnostic significance this morphological abnormality holds, potentially revolutionizing diagnostic practices within the field.

The male-to-female ratio in late-onset multiple acyl-CoA dehydrogenase deficiency: a systematic review and meta-analysis.

BACKGROUND: Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is the most common lipid storage myopathy. There are sex differences in fat metabolism and it is not known whether late-onset MADD affects men and women equally. METHODS: In this systematic review and meta-analysis, the PubMed, Embase, Web of Science, CNKI, CBM, and Wanfang databases were searched until 01/08/2023. Studies reporting sex distribution in patients with late-onset MADD were included. Two authors independently screened studies for eligibility, extracted data, and assessed risk of bias. Pre-specified outcomes of interest were the male-to-female ratio (MFR) of patients with late-onset MADD, the differences of clinical characteristics between the sexes, and factors influencing the MFR. RESULTS: Of 3379 identified studies, 34 met inclusion criteria, yielding a total of 609 late-onset MADD patients. The overall pooled percentage of males was 58% (95% CI, 54-63%) with low heterogeneity across studies (I2 = 2.99%; P = 0.42). The mean onset ages, diagnostic delay, serum creatine kinase (CK), and allelic frequencies of 3 hotspot variants in ETFDH gene were similar between male and female patients (P > 0.05). Meta-regressions revealed that ethnic group was associated with the MFR in late-onset MADD, and subgroup meta-analyses demonstrated that East-Asian patients had a higher percentage of male, lower CK, and higher proportion of hotspot variants in ETFDH gene than non-East-Asian patients (P < 0.05). CONCLUSIONS: Male patients with late-onset MADD were more common than female patients. Ethnicity was proved to be a factor influencing the MFR in late-onset MADD. These findings suggest that male sex may be a risk factor for the disease.

A comparative study on riboflavin responsive multiple acyl-CoA dehydrogenation deficiency due to variants in FLAD1 and ETFDH gene.

Lipid storage myopathy (LSM) is a heterogeneous group of lipid metabolism disorders predominantly affecting skeletal muscle by triglyceride accumulation in muscle fibers. Riboflavin therapy has been shown to ameliorate symptoms in some LSM patients who are essentially concerned with multiple acyl-CoA dehydrogenation deficiency (MADD). It is proved that riboflavin responsive LSM caused by MADD is mainly due to ETFDH gene variant (ETFDH-RRMADD). We described here a case with riboflavin responsive LSM and MADD resulting from FLAD1 gene variants (c.1588 C > T p.Arg530Cys and c.1589 G > C p.Arg530Pro, FLAD1-RRMADD). And we compared our patient together with 9 FLAD1-RRMADD cases from literature to 106 ETFDH-RRMADD cases in our neuromuscular center on clinical history, laboratory investigations and pathological features. Furthermore, the transcriptomics study on FLAD1-RRMADD and ETFDH-RRMADD were carried out. On muscle pathology, both FLAD1-RRMADD and ETFDH-RRMADD were proved with lipid storage myopathy in which atypical ragged red fibers were more frequent in ETFDH-RRMADD, while fibers with faint COX staining were more common in FLAD1-RRMADD. Molecular study revealed that the expression of GDF15 gene in muscle and GDF15 protein in both serum and muscle was significantly increased in FLAD1-RRMADD and ETFDH-RRMADD groups. Our data revealed that FLAD1-RRMADD (p.Arg530) has similar clinical, biochemical, and fatty acid metabolism changes to ETFDH-RRMADD except for muscle pathological features.

Clinical, biochemical, and genetic spectrum of MADD in a South African cohort: an ICGNMD study.

BACKGROUND: Multiple acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive disorder resulting from pathogenic variants in three distinct genes, with most of the variants occurring in the electron transfer flavoprotein-ubiquinone oxidoreductase gene (ETFDH). Recent evidence of potential founder variants for MADD in the South African (SA) population, initiated this extensive investigation. As part of the International Centre for Genomic Medicine in Neuromuscular Diseases study, we recruited a cohort of patients diagnosed with MADD from academic medical centres across SA over a three-year period. The aim was to extensively profile the clinical, biochemical, and genomic characteristics of MADD in this understudied population. METHODS: Clinical evaluations and whole exome sequencing were conducted on each patient. Metabolic profiling was performed before and after treatment, where possible. The recessive inheritance and phase of the variants were established via segregation analyses using Sanger sequencing. Lastly, the haplotype and allele frequencies were determined for the two main variants in the four largest SA populations. RESULTS: Twelve unrelated families (ten of White SA and two of mixed ethnicity) with clinically heterogeneous presentations in 14 affected individuals were observed, and five pathogenic ETFDH variants were identified. Based on disease severity and treatment response, three distinct groups emerged. The most severe and fatal presentations were associated with the homozygous c.[1067G > A];c.[1067G > A] and compound heterozygous c.[976G > C];c.[1067G > A] genotypes, causing MADD types I and I/II, respectively. These, along with three less severe compound heterozygous genotypes (c.[1067G > A];c.[1448C > T], c.[740G > T];c.[1448C > T], and c.[287dupA*];c.[1448C > T]), resulting in MADD types II/III, presented before the age of five years, depending on the time and maintenance of intervention. By contrast, the homozygous c.[1448C > T];c.[1448C > T] genotype, which causes MADD type III, presented later in life. Except for the type I, I/II and II cases, urinary metabolic markers for MADD improved/normalised following treatment with riboflavin and L-carnitine. Furthermore, genetic analyses of the most frequent variants (c.[1067G > A] and c.[1448C > T]) revealed a shared haplotype in the region of ETFDH, with SA population-specific allele frequencies of < 0.00067-0.00084%. CONCLUSIONS: This study reveals the first extensive genotype-phenotype profile of a MADD patient cohort from the diverse and understudied SA population. The pathogenic variants and associated variable phenotypes were characterised, which will enable early screening, genetic counselling, and patient-specific treatment of MADD in this population.

Riboflavin-responsive lipid-storage myopathy in elderly patients.

There are scarce reports of riboflavin-responsive lipid storage myopathy in elderly patients with onset in their sixties. We describe three elderly patients with riboflavin-responsive lipid-storage myopathy. All three patients (aged 67-71 years on first examination) had subacute onset of neck extensors and proximal limb weakness progressing to inability to rise from a sitting position or to walk. Muscle biopsies showed vacuoles with lipid content, mainly in type 1 fibers. Genetic analysis failed to identify any pathogenic variant in one patient, identified a heterozygous variant of uncertain significance c.812 A > G; p.Tyr271Cys in the ETFDH gene in the second patient, and revealed a heterozygote likely pathogenic variant c.1286-2 A > C in the ETFDH gene predicted to cause abnormal splicing in the third patient. All patients responded to treatment with riboflavin and carnitine, and regained normal strength. This report emphasizes the importance of muscle biopsy in revealing treatable lipid storage myopathy in elderly patients with progressive myopathy of unidentifiable cause.

A case report on multiple acyl-CoA dehydrogenase deficiency with severe myopathy and osteoporosis.

A 35-year-old male patient presented fluctuating bilateral lower extremity weakness for 3 years. Physical examination showed grade 4 proximal muscle weakness in both lower extremities and grade 5 distal muscle weakness. Laboratory data revealed elevated creatine kinase, triglycerides, and cholesterol. Muscle pathology showed deposition of lipid droplet under the sarcolemma. Bone densitometry indicated severe osteoporosis. Next-generation sequencing revealed a pathogenic mutation in the ETFDH gene. The patient was diagnosed with late-onset multiple acyl-CoA dehydrogenase deficiency. After riboflavin treatment, symptoms of the patient were relieved, physical endurance was restored, and bone mineral density was improved.

Riboflavin 1 Transporter Deficiency: Novel SLC52A1 Variants and Expansion of the Phenotypic Spectrum.

Riboflavin transporter 1 (RFVT1) deficiency is an ultrarare metabolic disorder due to autosomal dominant pathogenic variants in SLC52A1. The RFVT1 protein is mainly expressed in the placenta and intestine. To our knowledge, only five cases of RFVT1 deficiency from three families have been reported so far. While newborns and infants with SLC52A1 variants mainly showed a multiple acyl-CoA dehydrogenase deficiency-like presentation, individuals identified in adulthood were usually clinically asymptomatic. We report two patients with novel heterozygous SLC52A1 variants. Patient 1 presented at the age of 62 with mild hyperammonemia following gastroenteritis. An acylcarnitine analysis in dried blood spots was abnormal with a multiple acyl-CoA dehydrogenase deficiency-like pattern, and genetic analysis confirmed a heterozygous SLC52A1 variant, c.68C > A, p. Ser23Tyr. Patient 2 presented with recurrent seizures and hypsarrhythmia at the age of 7 months. Metabolic investigations yielded unremarkable results. However, whole exome sequencing revealed a heterozygous start loss variant, c.3G > A, p. Met1Ile in SLC52A1. These two cases expand the clinical spectrum of riboflavin transporter 1 deficiency and demonstrate that symptomatic presentation in adulthood is possible.

Late-onset multiple acyl-CoA dehydrogenase deficiency: an insidious presentation.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare inborn error of metabolism that results in impairment of mitochondrial ß-oxidation of fatty acids. It is inherited in an autosomal recessive manner and impairs electron transfer in the electron transport chain. The clinical manifestations of MADD are highly variable and include exercise intolerance, myopathy, cardiomyopathy, encephalopathy, coma and death. Early-onset MADD is often associated with a high mortality with significant number of patients presenting with severe metabolic acidosis, non-ketotic hypoglycaemia and/or hyperammonaemic presentations. While late-onset MADD is suggested to have a lower mortality, the severe encephalopathic presentations may well be under-reported as a diagnosis of MADD may not be considered.MADD is treatable with riboflavin and appropriate nutrition with a focus on prevention and early management of metabolic decompensation. The neonatal phenotype differs significantly from late-onset MADD, where diagnosis may be delayed due to heterogeneity in clinical features, atypical presentation and confounding comorbidities, together with lower awareness among physicians.This report describes a woman in her 30s who presented with acute-onset ataxia, confusion and hyperammonaemic encephalopathy requiring intubation. Subsequent biochemical investigation revealed a diagnosis of MADD. At present, there are no national guidelines in Australia for the management of MADD. This case highlights the investigation and treatment of late-onset MADD.

Generation of an induced pluripotent stem cell (iPSC) line (INNDSUi002-A) from a patient with riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency.

Mutations in the ETFDH gene, encoding electron transfer flavoprotein dehydrogenase, have been identified to cause riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency (RR-MADD) (Wen et al., 2010). We performed the generation and characterization of human induced pluripotent stem cell (iPSC) line from skin fibroblasts of a patient with RR-MADD carrying two heterozygous ETFDH mutations (p.D130V and p.A84V). Their pluripotency was verified by the expression of several pluripotency markers on RNA and protein levels and the capability to differentiate into all three germ layers.

Income and emotional well-being: A conflict resolved.

Do larger incomes make people happier? Two authors of the present paper have published contradictory answers. Using dichotomous questions about the preceding day, [Kahneman and Deaton, Proc. Natl. Acad. Sci. U.S.A. 107, 16489-16493 (2010)] reported a flattening pattern: happiness increased steadily with log(income) up to a threshold and then plateaued. Using experience sampling with a continuous scale, [Killingsworth, Proc. Natl. Acad. Sci. U.S.A. 118, e2016976118 (2021)] reported a linear-log pattern in which average happiness rose consistently with log(income). We engaged in an adversarial collaboration to search for a coherent interpretation of both studies. A reanalysis of Killingsworth's experienced sampling data confirmed the flattening pattern only for the least happy people. Happiness increases steadily with log(income) among happier people, and even accelerates in the happiest group. Complementary nonlinearities contribute to the overall linear-log relationship. We then explain why Kahneman and Deaton overstated the flattening pattern and why Killingsworth failed to find it. We suggest that Kahneman and Deaton might have reached the correct conclusion if they had described their results in terms of unhappiness rather than happiness; their measures could not discriminate among degrees of happiness because of a ceiling effect. The authors of both studies failed to anticipate that increased income is associated with systematic changes in the shape of the happiness distribution. The mislabeling of the dependent variable and the incorrect assumption of homogeneity were consequences of practices that are standard in social science but should be questioned more often. We flag the benefits of adversarial collaboration.

A novel deleterious ETFA promoter variant causative of multiple acyl-CoA dehydrogenase deficiency.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive disorder of fatty acid, amino acid, and choline metabolism. We describe a patient identified through newborn screening in which the diagnosis of MADD was confirmed based on metabolic profiling, but clinical molecular sequencing of ETFA, ETFB, and ETFDH was normal. In order to identify the genetic etiology of MADD, we performed whole genome sequencing and identified a novel homozygous promoter variant in ETFA (c.-85G > A). Subsequent studies showed decreased ETFA protein expression in lymphoblasts. A promoter luciferase assay confirmed decreased activity of the mutant promoter. In both assays, the variant displayed considerable residual activity, therefore we speculate that our patient may have a late onset form of MADD (Type III). Our findings may be helpful in establishing a molecular diagnosis in other MADD patients with a characteristic biochemical profile but apparently normal molecular studies.

Retrograde response to mitochondrial dysfunctions associated to LOF variations in FLAD1 exon 2: unraveling the importance of RFVT2.

Flavin adenine dinucleotide (FAD) synthase (EC 2.7.7.2), encoded by human flavin adenine dinucleotide synthetase 1 (FLAD1), catalyzes the last step of the pathway converting riboflavin (Rf) into FAD. FLAD1 variations were identified as a cause of LSMFLAD (lipid storage myopathy due to FAD synthase deficiency, OMIM #255100), resembling Multiple Acyl-CoA Dehydrogenase Deficiency, sometimes treatable with high doses of Rf; no alternative therapeutic strategies are available. We describe here cell morphological and mitochondrial alterations in dermal fibroblasts derived from a LSMFLAD patient carrying a homozygous truncating FLAD1 variant (c.745C > T) in exon 2. Despite a severe decrease in FAD synthesis rate, the patient had decreased cellular levels of Rf and flavin mononucleotide and responded to Rf treatment. We hypothesized that disturbed flavin homeostasis and Rf-responsiveness could be due to a secondary impairment in the expression of the Rf transporter 2 (RFVT2), encoded by SLC52A2, in the frame of an adaptive retrograde signaling to mitochondrial dysfunction. Interestingly, an antioxidant response element (ARE) is found in the region upstream of the transcriptional start site of SLC52A2. Accordingly, we found that abnormal mitochondrial morphology and impairments in bioenergetics were accompanied by increased cellular reactive oxygen species content and mtDNA oxidative damage. Concomitantly, an active response to mitochondrial stress is suggested by increased levels of PPARγ-co-activator-1α and Peroxiredoxin III. In this scenario, the treatment with high doses of Rf might compensate for the secondary RFVT2 molecular defect, providing a molecular rationale for the Rf responsiveness in patients with loss of function variants in FLAD1 exon 2.HIGHLIGHTSFAD synthase deficiency alters mitochondrial morphology and bioenergetics;FAD synthase deficiency triggers a mitochondrial retrograde response;FAD synthase deficiency evokes nuclear signals that adapt the expression of RFVT2.

The clinical, pathological, and genetic characteristics of lipid storage myopathy in northern China.

BACKGROUND: The lipid storage myopathy (LSM) diagnosis is based on the patient's clinical manifestations and muscle pathology. However, when genetic testing is lacking, there is a high rate of misdiagnosis of the disease. This study aimed to investigate the clinical and pathological features of genetically diagnosed LSM in northern China, analyze genetic mutations' characteristics, and improve the LSM diagnostic rate. METHODS: Twenty patients with LSM diagnosed were collected; meanwhile, the clinical data, muscle samples, and routine pathological staining of muscle specimens were collected. The morphological changes of muscle fibers were observed under an optical microscope. RESULTS: Among the included patients, 18 cases had ETFDH (HGNC ID: 3483) mutations, and two had PNPLA2 mutations. Family pedigree verification was performed on three patients with heterozygous mutations in the ETFDH gene complex. Histopathological staining showed that all patients had fine vacuoles in the muscle fibers, and some of them merged to form fissures, and the lipid droplets increased in cells. After therapy, 18 patients were associated with a favorable prognosis, and two patients were ineffective with the treatment of neutral lipid storage myopathy (NLSDM) caused by PNPLA2 mutation. DISCUSSION: The clinical manifestations of LSM are complex and diverse, mainly manifested by proximal muscle weakness and exercise intolerance in the extremities. The pathological images of LSM muscles are abnormal storage of lipid droplets in muscle fibers, primarily involving type I fibers. The LSM patients were mainly multiple acyl-CoA dehydrogenase deficiency (MADD) caused by the ETFDH gene mutation. It is necessary to perform an accurate typing diagnosis of LSM.

An unusual presentation of type III late onset multiple-acyl-CoA dehydrogenase deficiency leading to a review of its classification system.

Multiple-acyl-CoA dehydrogenase deficiency (MADD) is a rare autosomal recessive disorder which can be split into three types. Type III MADD is associated with acute or subacute proximal muscle weakness and other variable non-specific features making it a challenging diagnosis for the clinician. This case report describes MADD in a 64 year-old lady, thought to be one of the latest first presentations of the disease. Unusually for this condition, the initial presentation was with dyspnoea. Furthermore, since this case provides further evidence that gene variants can predict age of onset, we advocate for further subclassification of type III MADD into late onset MADD (LO-MADD) when homozygous gene variants are present and very LO-MADD when heterozygous gene variants are found.

Incorporating second-tier genetic screening for multiple acyl-CoA dehydrogenase deficiency.

BACKGROUND: Newborn screening (NBS) for multiple acyl-CoA dehydrogenase deficiency (MADD) has poor sensitivity. This study aimed to evaluate the feasibility of incorporating second-tier genetic screening for MADD. METHODS: A total of 453,390 newborns were screened for inherited metabolic disorders using tandem mass spectrometry from January 2017 to May 2022. A matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) assay was developed to identify 23 common ETFDH variants and used for second-tier screening of MADD. RESULTS: Overall, 185 newborns with suspected MADD received second-tier genetic screening. Thirty-three (17.8 %) newborns with positive results, of which 7 were homozygotes, 5 were compound heterozygotes, 21 were heterozygotes. Further genetic analysis revealed that 6 of the 21 newborns had a second ETFDH variant. Therefore, 18 patients were finally diagnosed with MADD, with a positive predictive value of 9.73 %. The detection rate and diagnostic rate of MALDI-TOF MS assay were 83.33 % and 66.67 %, respectively. Thus the incidence of MADD in our population was estimated at 1:25,188. Nine different ETFDH variants were identified in MADD patients. The most common ETFDH variant being c.250G > A with an allelic frequency of 47.22 %, followed by c.524G > A (13.89 %) and c.998A > G (13.89 %). All patients had elevation of multiple acylcarnitines at NBS. However, seven patients had normal acylcarnitine levels and two patients showed mild elevation of only two acylcarnitines during the recall review. CONCLUSION: We have established a high throughput MALDI-TOF MS assay for MADD screening. Half of the MADD patients would not be detected under conventional screening protocols. Incorporating second-tier genetic screening into the current NBS could improve the performance of MADD NBS.

Triagem neonatal por espectrometria de massas em tandem (MS/MS) para detecção da deficiência de acil-CoA desidrogenase de cadeia média (MCADD) / Neonatal screening by tandem mass spectrometry (MS/MS) for detection of medium-chain acyl-CoA dehydrogenase deficiency (MCADD)

INTRODUÇÃO: A MCADD é o distúrbio mais frequente da beta-oxidação mitocondrial dos ácidos graxos. No Brasil, a comparação de estudos epidemiológicos nacionais com dados da experiência do Distrito Federal com a triagem neonatal por MS/MS para MCADD sugerem um subdiagnóstico dessa condição no Brasil. A MCADD é uma doença grave, cujas manifestações clínicas geralmente iniciam no primeiro ano de vida. Os sintomas mais comuns incluem hipoglicemia hipocetótica recorrente, letargia, vômitos, disfunção hepática aguda, episódios semelhantes à síndrome de Reye, convulsões, coma e morte súbita. O seu diagnóstico precoce, possibilitado pela triagem neonatal por MS/MS, representa uma estratégia importante para a realização do tratamento oportuno e prevenção de óbitos e sequelas. TECNOLOGIA: Triagem neonatal por espectrometria de massas em tandem (MS/MS) em sangue seco, colhido em papelfiltro. PERGUNTA DE PESQUISA: A triagem neonatal (em sangue seco, colhido em papel-filtro) por MS/MS, para a detecção da MCADD, em recém-nascidos assintomáticos, é custo-efetiva e reduz a mortalidade e as complicações de curto e longo prazo naqueles recém-nascidos nos quais a doença é detectada, em comparação ao diagnóstico dessa doença em indivíduos com suspeita clínica ou manifestações clínicas? EVIDÊNCIAS CLINICAS: Em uma revisão sistemática da literatura, realizada em 26 de abril de 2022, foram encontradas 1037 referências, das quais 7 atendiam aos critérios de inclusão deste relatório (6 avaliaram desfechos primários e 1 avaliou desfechos secundários). Considerando os 4 desfechos primários avaliados, não foram encontrados estudos sobre apenas um deles (qualidade de vida). Os estudos incluídos descrevem maior frequência de morte súbita ou por complicações da doença, e de internações hospitalares decorrentes da doença ou de suas complicações no grupo comparador (indivíduos com suspeita clínica ou com manifestações clínicas de MCADD). Com relação à incidência de complicações ou condições resultantes da doença, independente da necessidade de admissão hospitalar, também há uniformidade entre os resultados dos estudos incluídos, indicando a eficácia/eficiência da intervenção. AVALIAÇÃO ECONÔMICA (AE) propôs-se uma análise de custo-utilidade construída com base nas diretrizes metodológicas publicadas pelo Ministério da Saúde, na perspectiva do SUS, tendo como população alvo todos os recém-nascidos no país. De acordo com a análise empreendida, o custo da triagem por MS/MS para MCADD foi de R$ 1.952,88, havendo um incremento em custos de cerca de R$ 1.949,00 em comparação à não-realização da triagem neonatal para esta doença. No entanto, a efetividade comparada da triagem por MS/MS foi superior à estratégia de não triar esta doença, mais do que o dobro daquela associada à não-triagem, havendo um incremento de cerca de 78 pontos nesta. Por fim, a Razão de Custo-efetividade Incremental (RCEI) encontrada foi de R$ 24,99/QALY. ANÁLISE DE IMPACTO ORÇAMENTÁRIO (AIO): foi feita uma avaliação do impacto orçamentário da possível incorporação do referido teste (MS/MS) ao longo de 5 anos, junto com a substituição da testagem para fenilcetonúria (PKU) pelo método de imunofluorimetria (o atualmente usado) pela mesma metodologia (MS/MS), conforme as Diretrizes Metodológicas de análise de Impacto Orçamentário do Ministério da Saúde. A realidade atual de inexistência de testagem de MCADD gera um custo anual em teste de triagem de zero. No entanto, a não identificação de indivíduos com MCADD, gera, por sua vez, custos de internação. Sendo assim, no primeiro caso o custo anual e em 5 anos seria zero. Porém se fossem considerados os custos gerados a partir dos pacientes sem diagnóstico neonatal que evoluíram a sintomas e internação no primeiro ano de vida, a estimativa em cinco anos seria de um gasto de pouco mais de R$ 100 mil. A triagem para MCADD por MS/MS descontados apenas os custos das internações evitadas com a identificação precoce daqueles com esta doença pela triagem, ficaria em cerca de R$ 288 milhões ao longo de 5 anos, sendo a média anual aproximadamente R$ 57 milhões. No entanto, considerando que a triagem por fenilcetonúria (PKU), hoje realizada por imunofluorimetria, com a adoção da triagem por MS/MS, poderia ser feita por esta última metodologia, sem que com isso houvesse acréscimo no gasto do exame realizado para MCADD (ou seja, o mesmo teste, triaria ao mesmo tempo MCADD e PKU) haveria uma economia adicional advinda dos custos salvos pela não realização da imunofluorimetria para PKU. Assim, ao considerar-se a triagem neonatal por MS/MS para MCADD e PKU ao longo de 5 anos, com todos os custos evitados (possíveis internações por sintomas da doença no primeiro ano de vida e utilização da imunofluorimetria como método da triagem para a fenilcetonúria), este valor seria cerca de R$ 222 milhões, resultando num dispêndio anual médio de cerca de R$ 44 milhões, ou seja, uma economia média anual adicional de 13 milhões apenas com a inclusão da triagem de PKU na mesma metodologia utilizada para triagem de MCADD. CONSIDERAÇÕES FINAIS: os resultados sugerem que os indivíduos com MCADD são beneficiados com a inclusão da triagem neonatal para a detecção dessa doença. A avaliação econômica mostra que a efetividade da triagem neonatal por MS/MS é de cerca de 153, sendo este valor mais que o dobro da efetividade associada à não-triagem (cerca de 75); a efetividade incremental é de 78. Já a RCEI encontrada foi de R$ 24,99/QALY. Esta análise indica ganhos evidentes da estratégia de adoção de triagem neonatal por MS/MS para MCADD. Em relação ao impacto econômico, ao longo de 5 anos, com todos os custos evitados (referentes às possíveis internações por sintomas da doença nos primeiros anos de vida e testagem conjunta de MCADD e PKU por MS/MS), este valor seria cerca de R$ 222 milhões, um dispêndio anual médio de cerca de R$ 44 milhões, uma economia média anual adicional de 13 milhões apenas com a inclusão da triagem de PKU na mesma metodologia utilizada para triagem de MCADD. RECOMENDAÇÃO PRELIMINAR DA CONITEC: na 113ª Reunião Ordinária da Conitec, realizada em 05 de outubro de 2022, os membros presentes no Plenário deliberaram por unanimidade que a matéria fosse disponibilizada em consulta pública com recomendação preliminar favorável à incorporação da triagem neonatal por espectrometria de massas em tandem (MS/MS), para a detecção da deficiência de MCADD. Para essa recomendação, a Conitec considerou que a detecção precoce por triagem neonatal da MCADD é eficaz, segura e custo-efetiva, estando de acordo com os critérios estabelecidos na Lei Nº 14.154, de 26 de maio de 2021, que dispõe sobre a ampliação do Programa Nacional de Triagem Neonatal (PNTN). CONSULTA PÚBLICA: : a consulta pública n° 70 ficou vigente no período entre 25/10/2022 e 14/11/2022. Foram recebidas 10 contribuições, sendo 4 da categoria técnico-científicas e 6 de experiência ou opinião. Todos os participantes estiveram de acordo com a recomendação preliminar da Conitec de incorporar a triagem neonatal por espectrometria de massas em tandem (MS/MS) para detecção da deficiência de acil-CoA desidrogenase de cadeia média (MCADD) no SUS. A consulta pública não adicionou elementos que alterassem o conteúdo deste relatório de recomendação. RECOMENDAÇÃO FINAL DA CONITEC: os membros do Plenário da Conitec, presentes em sua 12ª Reunião Extraordinária, realizada no dia 29 de novembro de 2022, deliberaram por unanimidade, recomendar a incorporação da triagem neonatal por espectrometria de massas em tandem (MS/MS) para detecção da deficiência de acilCoA desidrogenase de cadeia média (MCADD). Foi assinado o Registro de Deliberação nº 789/2022. DECISÃO: Incorporar, no âmbito do Sistema Único de Saúde - SUS, a triagem neonatal por espectrometria de massas em tandem (MS/MS) para detecção da deficiência de acilCoA desidrogenase de cadeia média (MCADD), conforme protocolo estabelecido pelo Ministério da Saúde, conforme a Portaria nº 179, publicada no Diário Oficial da União nº 244, seção 1, página 304, em 28 de dezembro de 2022.