Clinical, pathological and genetic features and follow-up of 110 patients with late-onset MADD: a single-center retrospective study.

To observe a long-term prognosis in late-onset multiple acyl-coenzyme-A dehydrogenation deficiency (MADD) patients and to determine whether riboflavin should be administrated in the long-term and high-dosage manner, we studied the clinical, pathological and genetic features of 110 patients with late-onset MADD in a single neuromuscular center. The plasma riboflavin levels and a long-term follow-up study were performed. We showed that fluctuating proximal muscle weakness, exercise intolerance and dramatic responsiveness to riboflavin treatment were essential clinical features for all 110 MADD patients. Among them, we identified 106 cases with ETFDH variants, 1 case with FLAD1 variants and 3 cases without causal variants. On muscle pathology, fibers with cracks, atypical ragged red fibers (aRRFs) and diffuse decrease of SDH activity were the distinctive features of these MADD patients. The plasma riboflavin levels before treatment were significantly decreased in these patients as compared to healthy controls. Among 48 MADD patients with a follow-up of 6.1 years on average, 31 patients were free of muscle weakness recurrence, while 17 patients had episodes of slight muscle weakness upon riboflavin withdrawal, but recovered after retaking a small-dose of riboflavin for a short-term. Multivariate Cox regression analysis showed vegetarian diet and masseter weakness were independent risk factors for muscle weakness recurrence. In conclusion, fibers with cracks, aRRFs and diffuse decreased SDH activity could distinguish MADD from other genotypes of lipid storage myopathy. For late-onset MADD, increased fatty acid oxidation and reduced riboflavin levels can induce episodes of muscle symptoms, which can be treated by short-term and small-dose of riboflavin therapy.

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.

[Consensus on screening, diagnosis and treatment of multiple acyl-CoA dehydrogenase deficiency].

Multiple acyl-CoA dehydrogenase deficiency (MADD), also known as glutaricacidemia type II, is a relatively common disorder of fatty acid oxidation metabolism. The clinical manifestations are highly heterogeneous, symptoms can develop from newborn to adulthood. Neonatal onset type is more serious with high mortality. The symptoms of late onset patients include lipid deposition myopathy and vomiting, liver disease, and encephalopathy. Analysis of blood acyl carnitine spectrum by tandem mass spectrometry can be used for the screening. Late onset patients have relatively good prognosis with vitamin B2 treatment. The purpose of this consensus is to standardize the diagnosis, treatment and management of MADD, so as to improve the prognosis of patients and reduce death and disability.

Screening of multiple acyl-CoA dehydrogenase deficiency in newborns and follow-up of patients.

To investigate the incidence rate, clinical and gene mutation characteristics of multiple acyl-CoA dehydrogenase deficiency (MADD) in newborns in Zhejiang province. A total of 3 896 789 newborns were screened for MADD using tandem mass spectrometry in Zhejiang Neonatal Screening Center during January 2009 and December 2020. Patients of MADD were confirmed by urine organic acid and electron transferring flavoprotein (or electron transferring flavoprotein dehydrogenase () gene detection. MADD patients were given diet and life management, supplemented with L-carnitine, riboflavin and coenzyme Q 10 treatment, and their growth and intellectual development were evaluated during the followed up.Thirteen patients with MADD were diagnosed, with an incidence of 1/299 753. One patient was type Ⅱ, and the rest were type Ⅲ. Patients were followed up for 1 case died, 4 cases had acute metabolic disorders with hypoglycemia as the main manifestation due to infection, 1 case had hypotonia, and the rest 7 cases developed well. Patients had raised levels of C4-C18:1 acylcarnitines in the initial screening. Thirteen children were genetically tested, 1 case with compound heterozygous mutation in the gene, 1 case with homozygous mutation in the gene, 1 case with compound heterozygous mutation in the gene, 8 cases with compound heterozygous mutation and 1 case with homozygous mutation in the gene, 1 case that only 1 locus of gene was detected. The c.250G>A was the hotspot mutation in this study.The clinical manifestations of MADD are highly heterogeneous. The neonatal-onset form is serious, and late onset form usually has no obvious clinical symptoms. C4-C18:1 acylcarnitines usually increased in the initial screening, and the hotspot gene mutation is c.250G>A.

Late-onset multiple acyl-CoA dehydrogenase deficiency mimicking myositis in an elderly patient: a case report.

BACKGROUND: Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare and treatable inherited lipid storage myopathy. Here, we report an elderly patient with MADD mimicking myositis. CASE PRESENTATION: An 80-year-old woman had progressive weakness in her limbs, exercise intolerance, and no muscle pain for 3 months. The patient's serum creatine kinase level was slightly elevated. The initial diagnosis was myositis. However, muscle biopsy showed many cytoplasmic vacuoles stained with oil red O, indicating the presence of lipid storage myopathy. The plasma acylcarnitine profile showed increased medium-chain and long-chain acylcarnitine species, consistent with the diagnosis of MADD. Riboflavin treatment dramatically improved muscle weakness. CONCLUSIONS: MADD should be considered when evaluating elderly patients with subacute muscle weakness.

Capillary electrophoresis with capacitively coupled contactless conductivity detection for the determination of urinary ethylmalonic acid for the diagnosis of ethylmalonic aciduria.

Ethylmalonic acid is a metabolic organic acid, and its accumulation in urine is diagnostic of ethylmalonic aciduria. In this study, a simple and fast method employing capillary electrophoresis equipped with capacitively coupled contactless conductivity detection was developed for the detection of ethylmalonic acid in urine samples. The optimized electrophoretic separation was performed in 50 mmol/L 2-(N-morpholino)ethanesulfonic acid solution, buffered at a pH of 6.5, and contained 0.13 mmol/L cetyltrimethylammonium bromide as an electroosmotic modifier. Electrophoresis was run at 28 kV in reversed polarity. The linear range of ethylmalonic acid concentration was between 1 and 100 mg/L with a regression coefficient of 0.9998. This method had good intra- and interday precision with <5% relative standard deviations. The detection limit (signal-to-noise ratio = 3) and the quantification limit (signal-to-noise ratio = 10) values were 0.139 and 0.466 mg/L, respectively. Using our optimized conditions, the method was successfully employed for the detection of ethylmalonic acid in urine sample of ethylmalonic aciduria patient.

Skin damage in a patient with lipid storage myopathy with a novel ETFDH mutation responsive to riboflavin.

Background: Recessive mutations in ETFDH gene have been associated with Multiple Acyl-CoA dehydrogenase deficiency (MADD). The late-onset MADD is often muscle involved, presenting with lipid storage myopathy (LSM). The symptoms of LSM were heterogeneous and definite diagnosis of this disease depends on the pathology and gene test.Methods: Neurological examination, muscle biopsy, and MRI examinations were performed in a patient with a novel missense ETFDH mutation.Results: We describe a patient with lipid storage myopathy complicated with skin damage. In addition, the next generation revealed a novel missense mutation (c.970G > T, p.Val324Leu) in exon 8, which was predicted to be a disease-causing mutation by Mutation-taster, and destroy the function of the protein by Sift.Conclusion: These findings expand the known mutational spectrum of ETFDH and phenotype of MADD.

[Diagnosis of glutaric acidemia type â ¡C by fetal whole exome sequencing].

OBJECTIVE: To explore the genetic basis of a fetus with enlargement and enhanced echo of the kidneys. METHODS: The imaging data of the fetus were collected, in addition with 20 mL amniotic fluid sample and 2 mL peripheral blood samples of both parents. Amniotic DNA was extracted for library construction and whole exome sequencing, and Sanger sequencing was carried out to verify candidate variant associated with the fetal phenotype. RESULTS: Prenatal ultrasound showed that the fetus had enlargement and enhanced echo of the kidneys, in addition with many small renal cysts. Whole exome sequencing showed that the fetus carried pathogenic compound heterozygous variants of the ETFDH gene, namely c.3G>C and c.1436dupA. Sanger sequencing of the family suggested that the variants were inherited from its mother and father, respectively. CONCLUSION: By combining its clinical manifestations and results of whole exome sequencing, the fetus was diagnosed as glutaric acidemia type ⅡC due to the compound heterozygous variants of the ETFDH gene. Above results have provided a basis for prenatal diagnosis and genetic counseling. Fetal exome sequencing has provided an important tool for prenatal diagnosis.

Follow-up of fatty acid ß-oxidation disorders in expanded newborn screening era.

Fatty acid ß-oxidation (FAO) disorders have a wide variety of symptoms, not usually evident between episodes of acute decompensations. Cardiac involvement is frequent, and severe ventricular arrhythmias are suspected of causing sudden death. Expanded newborn screening (ENS) for these disorders, hopefully, contribute to prevent potentially acute life-threatening events. In order to characterize acute decompensations observed in FAO-deficient cases identified by ENS, a retrospective analysis was performed, covering a period of 9 years. Demographic data, number/type of acute decompensations, treatment, and follow-up were considered. Eighty-three clinical charts, including 66 medium-chain acyl-CoA dehydrogenase deficiency (MCADD), 5 carnitine-uptake deficiency (CUD), 3 carnitine palmitoyltransferase I and II (CPT I/II) deficiency, 5 very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), and 4 multiple acyl-CoA dehydrogenase deficiency (MADD) cases were reviewed. Nineteen patients had acute decompensations (1 CPT I, 1 CPT II, 3 MADD, 14 MCADD). Six patients developed symptoms previously to ENS diagnosis. Severe clinical manifestations included multiple organ failure, liver failure, heart failure, and sudden death. Long-chain FAO disorders had the highest number of decompensations per patient.Conclusion: Despite earlier diagnosis by ENS, sudden deaths were not avoided and acute decompensations with severe clinical manifestations still occur as well. What is Known: • Severe ventricular arrhythmias are suspected to cause unexpected death in FAO disorders. • Neonatal screening intends to reduce the incidence of severe metabolic crisis and death. What is New: • Acute severe decompensations occurred in FAO disorders diagnosed through neonatal screening. • Sudden deaths were not avoided by starting treatment precociously.

[Tandem mass spectrometry analysis and genetic diagnosis of neonates with fatty acid oxidation disorders in central and northern regions of Guangxi].

OBJECTIVE: To determine the incidence and mutational types of fatty acid oxidation disorders (FAOD) in central-northern region of Guangxi. METHODS: A total of 62 953 neonates were screened for FAOD during December 2012 and December 2017. Acyl-carnitine profiling of neonatal blood sample was performed by tandem mass spectrometry using dry blood spots on a filter paper. The diagnosis of FAOD was confirmed by organic acid profiling of urea and genetic testing. RESULTS: Eighteen cases of FAOD were diagnosed among the 62 953 neonates. Among these, primary carnitine deficiency (PCD) was the most common type (n=13), which was followed by short-chain acyl-CoA dehydrogenase deficiency (SCADD) (n=2), medium-chain acyl-CoA dehydrogenase deficiency (MCADD) (n=1), multiple acyl-CoA dehydrogenase deficiency (MADD) (n=1), and carnitine palmitoyltransferase II deficiency (CPT II D) (n=1). Genetic testing has revealed two previously unreported variants, i.e., c.337G to A (p.Gly113Arg) of ACADS gene and c.737G TO T (p.Gly246Val) of ETFA gene. CONCLUSION: PCD is the most common FAOD in central-northern Guangxi. Tandem mass spectrometry combined with genetic testing may facilitate early diagnosis of FAOD.

Acute-onset multiple acyl-CoA dehydrogenase deficiency mimicking Guillain-Barré syndrome: two cases report.

BACKGROUND: Multiple acyl-CoA dehydrogenase deficiency (MADD) showed great clinical heterogeneity and poses a challenge to diagnosis. Guillain-Barré syndrome (GBS) is an acute-onset autoimmune-mediated peripheral neuropathy. However, no patients of acute-onset MADD mimicking the GBS phenotype are reported previously. CASE PRESENTATION: Two patients displayed acute-onset limb weakness, areflexia, and length-dependent sensory disturbances, which clinically indicate the diagnosis of GBS, but electrophysiological and cerebrospinal fluid results threw doubtful points to the initial diagnosis. The muscle biopsy showed lipid storage disorder; and compound heterozygous mutations in the electron transfer flavoprotein dehydrogenase (ETFDH) gene were found in the two patients through targeted next generation sequencing, which provided the definite diagnostic evidences of late-onset MADD. Muscle weakness was quickly improved by riboflavin supplementation, but sensory disturbances required a long-term treatment. DISCUSSION: The present two cases have demonstrated that MADD can mimic GBS. Taking into consideration the significant differences of therapeutic regimen and prognosis, MADD should be included in the differential diagnosis of GBS.

Myopathy with MTCYB mutation mimicking Multiple Acyl-CoA Dehydrogenase Deficiency.

We describe two patients with mitochondrial DNA mutations in the gene encoding cytochrome b (m.15579A>G, p.Tyr278Cys and m.15045G>A p.Arg100Gln), which presented as a pure myopathic form (exercise intolerance), with an onset in childhood. Diagnosis was delayed, because acylcarnitine profile showed an increase in medium and long-chain acylcarnitines, suggestive of multiple acyl-CoA dehydrogenase deficiency, riboflavin transporter deficiency or FAD metabolism disorder. Implication of cytochrome b in fatty acid oxidation, and physiopathology of the mutations are discussed.

[The 463rd case: rhabdomyolysis, acute kidney failure and acute hepatic failure].

We represented a 22-year-old male patient who developed rhabdomyolysis, acute kidney failure and acute hepatic failure and was finally diagnosed as multiple acyl-CoA dehydrogenase deficiency. The patient appeared temporary stable status after high dose vitamine-B(2) supplement whereas deterioration was still fatal with pulmonary infection, acute respiratory failure and acute heart failure.

Compound heterozygous mutations in electron transfer flavoprotein dehydrogenase identified in a young Chinese woman with late-onset glutaric aciduria type II.

BACKGROUND: Glutaric aciduria type II (GA II) is an autosomal recessive disorder affecting fatty acid and amino acid metabolism. The late-onset form of GA II disorder is almost exclusively associated with mutations in the electron transfer flavoprotein dehydrogenase (ETFDH) gene. Till now, the clinical features of late-onset GA II vary widely and pose a great challenge for diagnosis. The aim of the current study is to characterize the clinical phenotypes and genetic basis of a late-onset GAII patient. METHODS: In this study, we described the clinical and biochemical manifestations of a 23-year-old female Chinese patient with late-onset GA II, and performed genomic DNA-based PCR amplifications and sequence analysis of ETFDH gene of the whole pedigree. We also used in-silicon tools to analyze the mutation and evaluated the pathogenicity of the mutation according to the criteria proposed by American College of Medical Genetics and Genomics (ACMG). RESULTS: The muscle biopsy of this patient revealed lipid storage myopathy. Blood biochemical test and urine organic acid analyses were consistent with GA II. Direct sequence analysis of the ETFDH gene (NM_004453) revealed compound heterozygous mutations: c.250G > A (p.A84T) on exon 3 and c.920C > G (p.S307C) on exon 8. Both mutations were classified as "pathogenic" according to ACMG criteria. CONCLUSIONS: In conclusion, our study described the phenotype and genotype of a late-onset GA II patient, reiterating the importance of ETFDH gene screening in these patients.

[Paroxysmal muscle weakness, liver enlargement, and hypoglycemia in a boy].

A boy aged 11 years was admitted due to intermittent weakness and difficulty in walking for 6 years, and hepatomegaly, glycopenia and unconsciousness for 4 years. The laboratory examinations showed severe metabolic acidosis, hypoglycemia, and abnormal liver function. CT scan showed marked liver enlargement with fat density shadow. The boy was given fluid infusion, correction of acidosis, intravenous injection of glucose, L-carnitine, compound vitamin B, and coenzyme Q10, but he was in a persistent coma and it was difficult to correct refractory metabolic acidosis and hypoglycemia. The boy died. Blood and urinary organic acid screening and gene detection confirmed that the boy had late-onset glutaric aciduria type II (GAIIc) caused by electron-transferring-flavoprotein dehydrogenase (ETFDH) gene defect. GAIIc is an inherited metabolic disease with a low incidence, resulting in a high misdiagnosis rate. GAIIc should be considered for children with recurrent weakness or reduced activity endurance, hypoglycemia, and marked liver enlargement with abnormal liver function. Urinary organic acid analysis and blood tandem mass spectrometry can help with the early diagnosis of GAIIc, and ETFDH gene analysis helps to make a confirmed diagnosis.

Fulminant lipid storage myopathy due to multiple acyl-coenzyme a dehydrogenase deficiency.

INTRODUCTION: The lipid storage myopathies, primary carnitine deficiency, neutral lipid storage disease, and multiple acyl coenzyme A dehydrogenase deficiency (MADD), are progressive disorders that cause permanent weakness. These disorders of fatty acid metabolism and intracellular triglyceride degradation cause marked fat deposition and damage to muscle cells. METHODS: We describe a rapidly progressive myopathy in a previously healthy 33-year-old woman. Over 4 months, she developed a proximal and axial myopathy associated with diffuse myalgia and dysphagia, ultimately leading to respiratory failure and death. RESULTS: Muscle biopsy showed massive accumulation of lipid. Plasma acylcarnitine and urine organic acid analysis was consistent with MADD. This was confirmed by molecular genetic testing, which revealed 2 pathogenic mutations in the ETFDH gene. CONCLUSIONS: This report illustrates a late-onset case of MADD and reviews the differential diagnosis and evaluation of patients with proximal myopathy and excessive accumulation of lipid on muscle biopsy.

Bent spine syndrome as an initial manifestation of late-onset multiple acyl-CoA dehydrogenase deficiency: a case report and literature review.

BACKGROUND: Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive inherited disease of metabolic dysfunction clinically characterized by fluctuating proximal muscle weakness, excise intolerance, and dramatic riboflavin responsiveness. Dropped head syndrome can occasionally be observed in some severe patients with late-onset MADD; however, bent spine syndrome as an initial symptom had not been reported in patients with late-onset MADD. CASE PRESENTATION: A 46-year-old man lost the ability to hold his trunk upright, and had difficulty in raising his head, but he had no obvious symptoms of limb weakness. Meanwhile, he developed persistent numbness of limbs and lips around. Myopathological features and combined elevation of multiple acylcarnitines indicated that the axial myopathy might be caused by lipid storage myopathy. Cervical and lumbosacral MRI revealed a lot of abnormal signals diffusing along paravertebral muscles, while the abnormal signals almost disappeared after riboflavin treatment. Nerve conduction study indicated the patient suffering from predominantly sensory neuropathy and mildly motor neuropathy. Muscle pathology also demonstrated no typical neurogenic change, which was consistent with the electrophysiological findings. Causative mutations were found in the ETFDH gene. CONCLUSION: We report the first case of late-onset MADD with sensory neuropathy initially manifesting as bent spine syndrome and dropped head syndrome.

Multiple acyl-CoA dehydrogenation deficiency as decreased acyl-carnitine profile in serum.

We report a case with late onset riboflavin-responsive multiple acyl-CoA dehydrogenation deficiency (MADD) characterized by decreased acyl-carnitine profile in serum which is consistent with primary systemic carnitine deficiency (CDSP) while just the contrary to a typical MADD. This patient complained with muscle weakness, muscle pain and intermittent vomiting, and was diagnosed as polymyositis, received prednisone therapy before consulted with us. Muscle biopsy revealed mild lipid storage. The findings of serum acyl-carnitines were consistent with CDSP manifesting as decreased free and total carnitines in serum. But oral L-carnitine supplementation was not very effective to this patient and mutation analysis of the SLC22A5 gene for CDSP was normal. Later, another acyl-carnitine analysis revealed a typical MADD profile in serum, which was characterized by increased multiple acyl-carnitines. Compound heterozygous mutations were identified in electron transferring-flavoprotein dehydrogenase (ETFDH) gene which confirmed the diagnosis of MADD. After administration of riboflavin, he improved dramatically, both clinically and biochemically. Thus, late onset riboflavin-responsive MADD should be included in the differential diagnosis for adult carnitine deficiency.