Medium-chain acyl-CoA Dehydrogenase Deficiency Research Articles

Assessment of Parenting Stress Related to Treatment and Management of a Child With Medium Chain Acyl-CoA Dehydrogenase Deficiency Identified by Newborn Screening

Medium chain acyl-CoA dehydrogenase (MCAD) deficiency, the most common defect in β -oxidation of fatty acids, occurs in approximately 1 in 15 000 live births. With the disorder, intolerance to fasting, impaired ketogenesis, and hypoglycemic coma may lead to metabolic crisis and/or irreversible neurological impairment. Although most states now test newborns for MCAD, few publications address treatment of children with MCAD deficiency or the stress parents may experience in caring for their children. Parents of all children with MCAD deficiency identified by newborn screening and followed by the Biochemical Genetics Clinic in Washington State were surveyed via a questionnaire specific to MCAD to determine treatment and management practices and were given the Parenting Stress Index—Short Form questionnaire. Seventy-eight percent (n = 11) of eligible parents responded. The mean parenting stress score among respondents (60) was significantly lower (P = .01) than were normative levels for the US population (71). Openended survey questions indicated that clear guidelines for management and treatment, as well as personal and professional support, may contribute to the relatively low parenting stress levels recorded in this population, thus providing some insight into what services health care providers should offer to parents of a child with MCAD deficiency.

Allelic diversity in MCAD deficiency: The biochemical classification of 54 variants identified during 5 years of ACADM sequencing

Medium-chain acyl-coA dehydrogenase (MCAD) deficiency is a commonly detected fatty acid oxidation disorder and its diagnosis relies on both biochemical and molecular analyses. Over a 5-year period, sequencing all 12 exons of the MCAD gene ( ACADM) in our laboratory revealed a total of 54 variants in 549 subjects analyzed. As most molecular ACADM testing is referred for the follow-up of an abnormal newborn screening result obtained from an asymptomatic newborn, the identification of a novel DNA variant, or “variant of unknown significance (VUS),” presents clinicians with a dilemma. Frequently, the results of molecular analyses are correlated to biochemical findings, such as the concentration of octanoylcarnitine (C8) in plasma and the excretion of hexanoylglycine (HG) in urine. Here, we describe the classification of genotypes harboring at least one VUS through the comparison of C8 and HG values measured in individuals who are carriers of, or affected with, MCAD deficiency on the basis of the following genotypes: c.985A>G/wildtype, c.199T>C/c.985A>G and c.985A>G/c.985A>G. Our findings emphasize the importance of obtaining both plasma and urine when following up positive newborn screening results and may influence the way physicians counsel their asymptomatic patients about MCAD deficiency after genetic analysis.

Newborn screening for disorders of fatty‐acid oxidation: experience and recommendations from an expert meeting

Experience with new-born screening (NBS) for disorders of fatty-acid oxidation (FAOD) is now becoming available from an increasing number of programs worldwide. The spectrum of FAOD differs widely between ethnic groups. Incidence calculations from reports from Australia, Germany, and the USA of a total of 5,256,999 newborns give a combined incidence of all FAOD of approximately 1:9,300. However, it appears to be much lower in Asians. Consequently, a significant prevalence and evidence for a clear benefit of NBS is proven for medium-chain acyl-CoA dehydrogenase deficiency (MCAD) only in countries with a high percentage of Caucasians, with very-long-chain acyl-CoA dehydrogenase deficiency (VLCAD) and long-chain 3-hydroxy acyl-CoA dehydrogenase deficiency (LCHAD) being additional candidates. The long-term benefit for many disorders has still to be evaluated and will require international collaboration, especially for the rarest disorders. Short-chain acyl-CoA dehydrogenase deficiency (SCAD) [as well as Systemic carnitine transporter deficiency (CTD) and dienoyl-CoA reductase deficiency (DE-RED)] are conditions of uncertain clinical significance, but most FAOD have a spectrum of clinical presentations (healthy-death). Confirmatory diagnostic procedures should be agreed upon to ensure international comparability of results and evidence-based modifications. The case of short-chain acyl-CoA dehydrogenase deficiency (SCAD) deficiency shows that even inclusion of conditions without a clearly known natural course may prove useful with respect to gain of knowledge and consecutive exclusion of a biochemical abnormality without clinical significance, although this line of argument implies the existence of structured follow-up programs and bears ethical controversies. As a final conclusion, the accumulated evidence suggests all FAOD should to be included into tandem mass spectrometry (MS/MS)-based NBS programs provided sufficient laboratory performance is guaranteed.

Clinical outcome at 2 years following diagnosis of medium chain acyl coenzyme a dehydrogenase deficiency through newborn screening: findings from the prospective UK collaborative and british paediatric surveillance unit studies

Background Newborn screening for medium chain acyl coenzyme A dehydrogenase deficiency (MCADD) has been implemented in a number of countries, including England (April 2009) but there are few reports of clinical outcome in large-scale prospective studies. During a UK pilot screening phase, all screen positive babies were followed through the British Paediatric Surveillance Unit (BPSU) to ascertain clinical outcome. Aim To report the spectrum of screen-positive MCADD referrals over a 2-year period and clinical outcomes at 2 years following confirmed MCADD diagnosis. Methods Between 1 March 2004 and 28 February 2006, 102 children were referred as presumptive positive (average triplicate screening C8 ≥0.5μmol/L) among 738 242 newborns screened at age 5–8 days (screen positive prevalence 1.4 per 10 000). Blood acylcarnitines, urine organic acids and c.985→G status, with extended mutation analysis in all non-c.985→G homozygotes (HMZ), were measured in all cases. Results were reviewed using an agreed diagnostic algorithm by an independent expert panel who assigned children to one of four categories: MCADD of definite phenotype; MCADD of uncertain phenotype; carriers; not MCADD. Clinician-reported clinical outcome at 1 and 2 years was obtained by systematic follow-up of new diagnoses notified to the BPSU. Results Of 102 screen positive infants (12 Asian; 43 female), 86 were confirmed as MCADD (positive predictive value 84%): 60 of definite phenotype (47 c.985→G HMZ, 13 other genotypes of known pathogenicity); 26 of uncertain phenotype (all with genotypes of uncertain pathogenicity). 79/86 (92%) were notified to the BPSU, with complete follow-up in 76 and partial follow up in three. At 2 years, one serious clinical episode was reported, one child experienced apnoea following vaccination and one child was reported with developmental delay/poor growth. One child (c.985→G HMZ) died after the 2-year follow-up period (age 2 years 9 months) during an intercurrent illness. Conclusion The specificity of screening is high and prevalence of c.985A→G homozygosity (55%) is comparable to other international screening programmes. While clinical outcome among screened babies appears good, death can occur highlighting the importance of timely management of acute illnesses in children with MCADD and effective information for and education of parents. Further information on longer-term outcomes is needed.

An approach to the diagnosis of inherited metabolic disease

Inherited metabolic diseases (IMDs) pose a particular challenge to diagnosis. Although individually rare, improved diagnostics and greater awareness have shown that the incidence is much greater than previously thought. The...

Projected Costs, Risks, and Benefits of Expanded Newborn Screening for MCADD

To evaluate the cost-effectiveness of newborn screening for medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) incorporating quality-of-life effects for false-positive newborn screens and recommended dietary treatment. A computer simulation model was developed to predict costs and health outcomes for expanded newborn screening for MCADD compared with clinical identification. The modeled target population was a hypothetical cohort of 100 000 newborns in the United States. Probabilities, costs, and quality-of-life weights were derived from a long-term follow-up study of newborn screening compared with clinical identification, primary data collection, published data, and expert opinion. We used a lifetime time horizon and the societal perspective. The main outcome measure was the incremental cost-effectiveness ratio in dollars per quality-adjusted life-year (QALY) gained. Secondary outcomes included averted deaths and hospitalizations. Using base-case assumptions, the cost-effectiveness of newborn screening for MCADD was $21 273 per QALY gained. The cost-effectiveness ratio increased to $21 278/QALY when the loss in quality of life associated with false-positive test results was incorporated and to $27 423/QALY when the quality of life associated with lifelong dietary recommendations for treating MCADD was incorporated. Results were sensitive to the false-positive rate for the newborn screening test and the cost of the initial screen. Expanded newborn screening for MCADD is cost-effective compared with well-accepted pediatric health interventions. Losses in quality of life associated with dietary treatment for MCADD, however, may offset some of the gains in QALYs from newborn screening. Consideration of new disorders for expanded newborn screening panels should include the potential reduction in quality of life associated with treatments.

Lack of genotype–phenotype correlations and outcome in MCAD deficiency diagnosed by newborn screening in New York State

Introduction: Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is one of the most common inborn errors of metabolism. Affected patients have impaired ability to break down medium chain fatty acids during fasting, and typically present in the early years of life with hypoketotic hypoglycemia, Reye syndrome-like symptoms, brain damage or death. The development of newborn screening (NBS) for MCAD deficiency has greatly improved outcome, but some patients still appear at risk for severe complications. We reviewed the outcome of patients identified with MCAD deficiency by the New York State NBS process to identify biochemical or genotypic markers which might predict outcome. Method: All eight NBS follow-up centers in New York State contributed the cases of MCAD deficiency diagnosed by newborn screen, who received diagnostic and follow-up care in their clinic. Data reviewed included gender, age, birthweight, initial NBS octanoylcarnitine level (C8) and C8/C2 ratio, follow-up C8 and hexanoylglycine, race/ethnicity, and presence of neonatal or later symptoms. Results: We identified 53 cases of MCAD deficiency. More than one quarter of patients had a post-neonatal symptomatic admission (predominantly lethargy associated with an intercurrent illness). No genotype or C8 level was protective for neonatal or later symptoms. There was a relationship between initial C8 level or C8/C2 ratio and occurrence of later symptoms (7.3μmol/L in the asymptomatic vs. 19.1μmol/L in the symptomatic, p<0.0002 for C8, and 0.26 vs. 0.6, respectively, for C8/C2 ratio, p<0.012). Four infants had initial C8 level >30μmol/L; these infants had a high rate of symptomatic or multiple symptomatic episodes or a history of sibling death from “SIDS”, and typically had deletion, nonsense or splice sites mutations. Infants having a history of a symptomatic episode were more likely to have higher initial C8 on NBS and a genotype predicted to strongly affect protein function. In our ethnically diverse group of patients, the c.985A>G mutation was rarely found in non-Caucasians. Discussion: No genotype or metabolite profile is protective from symptoms. The strong relationship between initial C8 level and outcome suggests that in at least some cases neonates having high initial C8 levels may be demonstrating an increased susceptibility to catabolic stress, and may merit additional precautions. Our data also suggest that these infants are more likely to carry severe mutations including homozygosity for the common mutation, deletions, nonsense or splice site mutations. The reports of significant lethargy or hypoglycemia during intercurrent illness in over one quarter of cases even when early medical intervention is recommended (and even when initial C8 is not profoundly elevated) underscores the importance of continued vigilance to prevent stressful fasting in this disorder.

Adult presentations of medium‐chain acyl‐CoA dehydrogenase deficiency (MCADD)

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessive disorder of mitochondrial fatty acid oxidation which is usually diagnosed in infancy or through neonatal screening. In the absence of population screening, adults with undiagnosed MCADD can be expected. This review discusses 14 cases that were identified during adulthood. The mortality of infantile patients is approximately 25% whereas in this adult case series it was shown it to be 50% in acutely presenting patients and 29% in total. Therefore, undiagnosed individuals are at risk of sudden fatal metabolic decompensation with high mortality. This review illustrates the need to consider the possibility of a fatty acid oxidation defect in an adult who presents with unexplained sudden clinical deterioration, particularly if precipitated by fasting or alcohol consumption. A history of unexplained sibling death may also raise the index of suspicion. There also needs to be appropriate clinical support for those patients identified clinically or as a result of family studies (sibling or parent).

A Neonatal Death Due to Medium-Chain Acyl-CoA Dehydrogenase Deficiency

We report a perinatal death due to medium-chain acyl-CoA dehydrogenase deficiency, which was referred to the Coroner's Physician as sudden unexplained infant death. Detailed death investigation including the autopsy findings, and newborn biochemical and molecular studies revealed the cause and natural manner of death. This disorder affects fatty acid oxidation and results in decreased tolerance for fasting, which can be life threatening. This case illustrates the critical role of newborn screening in the investigation of perinatal death. A brief historical perspective of the origins of newborn biochemical screening is also presented.

Evidence that the major metabolites accumulating in medium-chain acyl-CoA dehydrogenase deficiency disturb mitochondrial energy homeostasis in rat brain

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an inherited metabolic disorder of fatty acid oxidation in which the affected patients predominantly present high levels of octanoic (OA) and decanoic (DA) acids and their glycine and carnitine by-products in tissues and body fluids. It is clinically characterized by episodic encephalopathic crises with coma and seizures, as well as by progressive neurological involvement, whose pathophysiology is poorly known. In the present work, we investigated the in vitro effects of OA and DA on various parameters of energy homeostasis in mitochondrial preparations from brain of young rats. We found that OA and DA markedly increased state 4 respiration and diminished state 3 respiration as well as the respiratory control ratio, the mitochondrial membrane potential and the matrix NAD(P)H levels. In addition, DA-elicited increase in oxygen consumption in state 4 respiration was partially prevented by atractyloside, indicating the involvement of the adenine nucleotide translocator. OA and DA also reduced ADP/O ratio, CCCP-stimulated respiration and the activities of respiratory chain complexes. The data indicate that the major accumulating fatty acids in MCADD act as uncouplers of oxidative phosphorylation and as metabolic inhibitors. Furthermore, DA, but not OA, provoked a marked mitochondrial swelling and cytochrome c release from mitochondria, reflecting a permeabilization of the inner mitochondrial membrane. Taken together, these data suggest that OA and DA impair brain mitochondrial energy homeostasis that could underlie at least in part the neuropathology of MCADD.

Validation of MCADD newborn screening

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) represents a potentially fatal fatty acid beta-oxidation disorder. Newborn screening (NBS) by tandem mass spectrometry (MS/MS) has been implemented worldwide, but is associated with unresolved questions regarding population heterogeneity, burden on healthy carriers, cut-off policies, false-positive and negative rates. In a retrospective case-control study, 333 NBS samples showing borderline acylcarnitine patterns but not reaching recall criteria were genotyped for the two most common mutations (c.985A>G/c.199C>T) and compared with genotypes and acylcarnitines of 333 controls, 68 false-positives, and 34 patients. c.985A>G was more frequently identified in the study group and false-positives compared to controls (1:4.3/1:2.3 vs. 1:42), whereas c.199C>T was found more frequently only within the false-positives (1:23). Biochemical criteria were devised to differentiate homozygous (c.985A>G), compound heterozygous (c.985A>G/c.199C>T), and heterozygous individuals. Four false-negatives were identified because our initial algorithm required an elevation of octanoylcarnitine (C(8)) and three secondary markers in the initial and follow-up sample. The new approach allowed a reduction of false-positives (by defining high cut-offs: 1.4 micromol/l for C(8); 7 for C(8)/C(12)) and false-negatives (by sequencing the ACADM gene of few suspicious samples). Our validation strategy is able to differentiate healthy carriers from patients doubling the positive predictive value (42-->88%) and to target NBS to MCADD-subsets with potentially higher risk of adverse outcome. It remains controversial, if NBS programs should aim at identifying all subsets of all diseases included. Because the natural course of milder variants cannot be assessed by observational studies, our strategy could serve as a general model for evaluation of MS/MS-based NBS.

Expanded Newborn Screening: Outcome in Screened and Unscreened Patients at Age 6 Years

Tandem mass spectrometry is widely applied to routine newborn screening but there are no long-term studies of outcome. We studied the clinical outcome at six years of age in Australia. In a cohort study, we analyzed the outcome at 6 years for patients detected by screening or by clinical diagnosis among >2 million infants born from 1994 to 1998 (1,017,800, all unscreened) and 1998 to 2002 (461,500 screened, 533,400 unscreened) recording intellectual and physical condition, school placement, other medical problems, growth, treatment, diet, and hospital admissions. Results were analyzed separately for medium-chain acyl-CoA dehydrogenase deficiency (MCADD) and other disorders, and grouped patients as those who presented clinically or died in the first 5 days of life; patients presented later or diagnosed by screening, and those with substantially benign disorders. Inborn errors, excluding phenylketonuria, were diagnosed in 116 of 1,551,200 unscreened infants (7.5/100,000 births) and 70 of 461,500 screened infants (15.2/100,000 births). Excluding MCADD, 21 unscreened patients with metabolic disorders diagnosed after 5 days of life died or had a significant intellectual or physical handicap (1.35/100,000 population) compared with 2 of the screened cohort (0.43/100,000; odds ratio: 3.1 [95% CI: 0.73-13.32]). Considering the likely morbidity or mortality among the expected number of never-diagnosed unscreened patients, there would be a significant difference. Growth distribution was normal in all cohorts. Screening by tandem mass spectrometry provides a better outcome for patients at 6 years of age, with fewer deaths and fewer clinically significant disabilities.

STN-DBS ACTIVATES THE TARGET AREA IN PARKINSON DISEASE

<h3>Introduction</h3> Limited research has focused on the health system impact of rare genetic disorders, including inborn errors of metabolism (IEM). Investigating patterns of health services use and their association with social and geographic characteristics is important for understanding the burden of disease, including the impact of screening and clinical management; and for identifying potential inequities in access to care. <h3>Objectives</h3> We conducted an observational study to provide a comprehensive description of the epidemiology and health system impact of IEM in Ontario, beginning with medium-chain acyl-CoA dehydrogenase deficiency (MCADD). <h3>Methods</h3> The study cohorts consist of Ontario infants diagnosed with MCADD following a positive newborn screening result from April 2006 through March 2010 (n=45); and those who received a false positive screening result for MCADD during the same time period (n=51). The primary control population includes a random sample of infants with negative screening results. Two distinct secondary control groups were created by matching to the truly affected cohort and the false-positive cohort, respectively. Screening and confirmatory testing results are securely linked at the individual level with population-based administrative databases encompassing health services use (physician visits, hospitalizations, and emergency department care) for all insured Ontarians from April 2006 through March 2012. Based on the results of a literature review we conducted to identify existing approaches to addressing statistical reliability with small sample sizes, analyses are largely descriptive. <h3>Results</h3> We will describe: (i) the patterns of health care services use overall and by sociodemographic and geographic characteristics, (ii) the associations between types of service use and proxy health outcomes, and (iii) the costs of care.

Tolerance to fast: rational and practical evaluation in children with hypoketonaemia

Prolonged fasting in children with disorder of fat oxidation or ketone body synthesis can lead not only to hypoglycaemia but also to the accumulation of toxic metabolites. The length of time such patients can be safely fasted is important information for caregivers. Most children with MCAD deficiency when well can tolerate 'normal' periods without food, but in more severe disorders such as LCHAD deficiency even these may be associated with acute or chronic damage. Guidelines have been published for safe fasting periods in MCAD but not in other conditions. In the absence of such recommendations, a rational approach must be based on an understanding of the normal physiology of fasting in children of different ages and the pathophysiology associated with the child's particular disorder. Intercurrent infections pose a particular risk and may significantly reduce fasting tolerance.

Medium-chain fatty acids accumulating in MCAD deficiency elicit lipid and protein oxidative damage and decrease non-enzymatic antioxidant defenses in rat brain

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most frequent disorder of fatty acid oxidation with a similar prevalence to that of phenylketonuria. Affected patients present tissue accumulation of the medium-chain fatty acids octanoate (OA), decanoate (DA) and cis-4-decenoate. Clinical presentation is characterized by neurological symptoms, such as convulsions and lethargy that may develop into coma and sudden death. The aim of the present work was to investigate the in vitro effect of OA and DA, the metabolites that predominantly accumulate in MCADD, on oxidative stress parameters in rat cerebral cortex homogenates. It was first verified that both DA and OA significantly increased chemiluminescence and thiobarbituric acid-reactive species levels (lipoperoxidation) and decreased the non-enzymatic antioxidant defenses, measured by the decreased total antioxidant capacity. DA also enhanced carbonyl content and oxidation of sulfhydryl groups (protein damage) and decreased reduced glutathione (GSH) levels. We also verified that DA-induced GSH decrease and sulfhydryl oxidation were not observed when cytosolic preparations (membrane-free supernatants) were used, suggesting a mitochondrial mechanism for these actions. Our present data show that the medium-chain fatty acids DA and OA that most accumulate in MCADD cause oxidative stress in rat brain. It is therefore presumed that this pathomechanism may be involved in the pathophysiology of the neurologic symptoms manifested by patients affected by MCADD.

Protein misfolding is the molecular mechanism underlying MCADD identified in newborn screening

Newborn screening (NBS) for medium-chain acyl-CoA dehydrogenase deficiency (MCADD) revealed a higher birth prevalence and genotypic variability than previously estimated, including numerous novel missense mutations in the ACADM gene. On average, these mutations are associated with milder biochemical phenotypes raising the question about their pathogenic relevance. In this study, we analyzed the impact of 10 ACADM mutations identified in NBS (A27V, Y42H, Y133H, R181C, R223G, D241G, K304E, R309K, I331T and R388S) on conformation, stability and enzyme kinetics of the corresponding proteins. Partial to total rescue of aggregation by co-overexpression of GroESL indicated protein misfolding. This was confirmed by accelerated thermal unfolding in all variants, as well as decreased proteolytic stability and accelerated thermal inactivation in most variants. Catalytic function varied from high residual activity to markedly decreased activity or substrate affinity. Mutations mapping to the β-domain of the protein predisposed to severe destabilization. In silico structural analyses of the affected amino acid residues revealed involvement in functionally relevant networks. Taken together, our results substantiate the hypothesis of protein misfolding with loss-of-function being the common molecular basis in MCADD. Moreover, considerable structural alterations in all analyzed variants do not support the view that novel mutations found in NBS bear a lower risk of metabolic decompensation than that associated with mutations detected in clinically ascertained patients. Finally, the detailed insight into how ACADM missense mutations induce loss of MCAD function may provide guidance for risk assessment and counseling of patients, and in future may assist delineation of novel pharmacological strategies.

Bloodspot acylcarnitine and amino acid analysis in cord blood samples: efficacy and reference data from a large cohort study

In order to test the feasibility of cord blood screening for inherited metabolic disease, a two-year cohort study of births in six obstetric units from five towns in the north of England was undertaken. These towns have a high prevalence of consanguineous marriages, largely among the immigrant Asian community. The purpose of the study was to determine whether early detection of metabolic disease was possible and whether early intervention would improve prognosis. Following parental consent, cord blood samples were collected at birth and analysed for acylcarnitine and amino acid profiles by tandem mass spectrometry in one of two laboratories. One laboratory used butylated derivatives, the other used underivatized samples. The same laboratories performed routine blood spot neonatal screening at 5-7 days of age on these babies. Patients with positive results were investigated and treated by a metabolic paediatrician as soon as possible. 24,983 births were examined. 12,952 samples were analysed as butyl derivatives, 12,031 samples were analysed underivatized. The following disorders were detected: medium-chain acyl-CoA dehydrogenase (MCAD) deficiency (1 case), 3-methylcrotonyl-CoA carboxylase (MCC) deficiency (2 cases), maternal carnitine transporter defect (2 cases), maternal MCC (1 case). The following disorders were diagnosed subsequently but were not detected by the cord blood screening: phenylketonuria (PKU) (1 case), maple syrup urine disease (MSUD) (2 cases), argininosuccinic aciduria (1 case), methylmalonic acidaemia (MMA) (1 case), glutaric aciduria type 2 (1 case), MCAD deficiency (2 cases), 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (1 case). Comprehensive reference data for all analytes by both methods were obtained. Cord blood testing is of limited value in detecting inherited metabolic disease. The metabolites associated with most disorders examined were not elevated in cord blood. Some maternal disorders, carnitine transporter defect and 3-methlycrotonyl-CoA carboxylase deficiency, are detected. These remain of uncertain clinical significance. Comprehensive reference data have been obtained that will facilitate future interpretation of studies in cord blood.

Medium-Chain Acyl-CoA Dehydrogenase Deficiency in an Infant with Dilated Cardiomyopathy

We report about an infant affected by dilated cardiomyopathy (CMP) in whom metabolic investigations evidenced medium-chain-acyl-CoA dehydrogenase deficiency (MCADD), that is one of three types of inherited disorders of mitochondrial fatty-acid β-oxidation. Long-chain and very long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficits are recognized as responsible of hypertrophic or, less frequently, dilated cardiomyopathy (CMP) in childhood. Otherwise, to our knowledge, no case of MCADD associated to dilated CMP has been reported in literature.

A985G mutation incidence in the medium-chain acyl-CoA dehydrogenase (MCAD) gene in Brazil

In view of the serious consequences of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency and the absence of information about its incidence in the Brazilian population, we examined the frequency of the A985G mutation in the MCAD gene. A retrospective analysis was made of data on 1722 individuals (844 females) genotyped for the A985G mutation in the MCAD gene, using genomic DNA extracted from peripheral blood leukocytes and genotyping with PCR-RFLP; 0.41% of these individuals were heterozygous for the A985G mutation. The mutant homozygous genotype was not found. The 985G mutant and 985A normal alleles had allelic frequencies of 0.0020 and 0.9980, respectively. Given the A985G allele frequency, genotyping would be recommended in cases of family history of MCAD deficiency and sudden infant death syndrome, and when there is suspicion of medium-chain fatty acid metabolic alterations; genetic counseling should be offered in cases involving 985GG and A985G individuals and consanguineous marriages.

Perioperative management of an adult patient with heterozygous medium chain acyl CoA dehydrogenase deficiency: a case report

Medium chain acyl CoA dehydrogenase (MCAD) deficiency is the most common disorder of beta-oxidation of fatty acids. The disease usually presents in childhood with episodes of hypoketotic hypoglycemic coma. Patients are particularly vulnerable during episodes of metabolic disruption, such as infection, surgery or starvation, which if left undetected can result in progressive multiple organ damage or even death. The enhanced recognition of heterozygous patients and the effective management of their metabolic milieu are likely to increase the prevalence of MCAD deficiency in the adult population, which will result in more adult patients with MCAD deficiency as a co-morbidity presenting for surgery. The disease has significant perioperative implications, and awareness about the condition and simple measures can significantly affect outcome. In this report, we describe uneventful anesthetic management during an emergent laparoscopic ovarian cystectomy in an adult female patient with compound heterozygous MCAD deficiency.