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Detection of Early Onset Carnitine Palmitoyltransferase II Deficiency by Newborn Screening: Should CPT II Deficiency Be a Primary Disease Target? Int J Neonatal Screen 2021; 7:ijns7030055. [PMID: 34449523 PMCID: PMC8395870 DOI: 10.3390/ijns7030055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Early-onset carnitine palmitoyltransferase II deficiency (CPT II deficiency) (OMIM 600650) can result in severe outcomes, which are often fatal in the neonatal to infantile period. CPT II deficiency is a primary target in the Maritime Newborn Screening Program. We report a case of neonatal-onset CPT II deficiency identified through expanded newborn screening with tandem mass spectrometry. Identification through newborn screening led to early treatment interventions, avoidance of metabolic decompensation, and a better clinical outcome. Newborn screening for CPT II deficiency is highly sensitive and specific with no false positives identified. The only screen positive case detected identified a true positive case. This experience illustrates the importance of newborn screening for CPT II deficiency and demonstrates why reconsideration should be taken to add this disease as a primary newborn screening target.
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Cox KB, Liu J, Tian L, Barnes S, Yang Q, Wood PA. Cardiac hypertrophy in mice with long-chain acyl-CoA dehydrogenase or very long-chain acyl-CoA dehydrogenase deficiency. J Transl Med 2009; 89:1348-54. [PMID: 19736549 PMCID: PMC2787798 DOI: 10.1038/labinvest.2009.86] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cardiac hypertrophy is a common finding in human patients with inborn errors of long-chain fatty acid oxidation. Mice with either very long-chain acyl-coenzyme A dehydrogenase deficiency (VLCAD-/-) or long-chain acyl-coenzyme A dehydrogenase deficiency (LCAD-/-) develop cardiac hypertrophy. Cardiac hypertrophy, initially measured using heart/body weight ratios, was manifested most severely in LCAD-/- male mice. VLCAD-/- mice, as a group, showed a mild increase in normalized cardiac mass (8.8% hypertrophy compared with all wild-type (WT) mice). In contrast, LCAD-/- mice as a group showed more severe cardiac hypertrophy (32.2% increase compared with all WT mice). On the basis of a clear male predilection, we analyzed the role of dietary plant estrogenic compounds commonly found in mouse diets because of soy or alfalfa components providing natural phytoestrogens or isoflavones in cardioprotection of LCAD-/- mice. Male LCAD-/- mice fed an isoflavone-free test diet had more severe cardiac hypertrophy (58.1% hypertrophy compared with WT mice fed the same diet). There were no significant differences in the female groups fed any of the diets. Echocardiography measurement performed on male LCAD-deficient mice fed a standard diet at the age of approximately 3 months confirmed the substantial cardiac hypertrophy in these mice compared with WT controls. Left ventricular (LV) wall thickness of the interventricular septum and posterior wall was remarkably increased in LCAD-/- mice compared with that of WT controls. Accordingly, the calculated LV mass after normalization to body weight was increased by about 40% in the LCAD-/- mice compared with WT mice. In summary, we found that metabolic cardiomyopathy, expressed as hypertrophy, developed in mice because of either VLCAD deficiency or LCAD deficiency; however, LCAD deficiency was the most profound and seemed to be attenuated either by endogenous estrogen (in females) or by phytoestrogens present in the diet as isoflavones (in males).
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Affiliation(s)
- Keith B. Cox
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Jian Liu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Liqun Tian
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Stephen Barnes
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama, 35294,Department of Purdue University-University of Alabama at Birmingham Botanicals Center for Age-related Disease, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Qinglin Yang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Philip A. Wood
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294,Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294,Burnham Institute for Medical Research, Orlando, Florida 32827
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Guo Z. Intramyocellular lipids: maker vs. marker of insulin resistance. Med Hypotheses 2007; 70:625-9. [PMID: 17766054 PMCID: PMC2288617 DOI: 10.1016/j.mehy.2007.03.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Accepted: 03/23/2007] [Indexed: 11/28/2022]
Abstract
Intramyocellular triglyceride (imcTG) content in skeletal muscle is abnormally high in lipid oversupply models in obesity, type 2 diabetes (T2D) and other metabolically diseased conditions. The imcTG abnormality was also found to be significantly correlated with muscle insulin resistance (MIR). As skeletal muscle is the main site for insulin-mediated glucose utilization, the research on this topic has been active since. However, to date the pathways responsible for the imcTG excess and the mechanisms underlying the imcTG-MIR correlation have not been identified. A current view is focused on a backward mechanism that fatty acid oxidation by muscle is impaired causing imcTG to accumulate and, therefore, an enlarged imcTG pool is merely a marker of MIR. However, based on kinetic studies, it is more likely that imcTG is a source of MIR. On one hand, an enlarged and fast turning over imcTG pool interferes with insulin signaling by producing excess amounts of signaling molecules that activate PKC pathways. On the other hand, it may promote mitochondrial beta-oxidation that suppresses glucose metabolism via substrate competition. Therefore, it is hypothesized that imcTG is a source of MIR.
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Affiliation(s)
- Zengkui Guo
- Endocrine Research Unit, 5-194 Joseph, Mayo Foundation, Rochester, MN 55905, United States.
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Guo Z. Intramyocellular lipid kinetics and insulin resistance. Lipids Health Dis 2007; 6:18. [PMID: 17650308 PMCID: PMC1971250 DOI: 10.1186/1476-511x-6-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 07/24/2007] [Indexed: 12/31/2022] Open
Abstract
More than fifteen years ago it was discovered that intramyocellular triglyceride (imcTG) content in skeletal muscle is abnormally high in conditions of lipid oversupply (e.g. high fat feeding) and, later, obesity, type 2 diabetes (T2D) and other metabolic conditions. This imcTG excess is robustly associated with muscle insulin resistance (MIR). However, to date the pathways responsible for the imcTG excess and the mechanisms underlying the imcTG-MIR correlation remain unclear. A current hypothesis is based on a backward mechanism that impaired fatty acid oxidation by skeletal muscle causes imcTG to accumulate. As such, imcTG excess is considered a marker but not a player in MIR. However, recent results from kinetic studies indicated that imcTG pool in high fat-induced obesity (HFO) model is kinetically dynamic. On one hand, imcTG synthesis is accelerated and contributes to imcTG accumulation. On the other, the turnover of imcTG is also accelerated. A hyperdynamic imcTG pool can impose dual adverse effects on glucose metabolism in skeletal muscle. It increases the release and thus the availability of fatty acids in myocytes that may promote fatty acid oxidation and suppress glucose utilization. Meanwhile, it releases abundant fatty acid products (e.g. diacylglycerol, ceramides) that impair insulin actions via signal transduction, thereby causing MIR. Thus, intramyocellular fatty acids and their products released from imcTG appear to function as a link to MIR. Accordingly, a forward mechanism is proposed that explains the imcTG-MIR correlation.
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Affiliation(s)
- ZengKui Guo
- Endocrine Research Unit, Mayo Foundation, Rochester, Minnesota 55905, USA.
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Skinner JR, Chong B, Fawkner M, Webster DR, Hegde M. Use of the newborn screening card to define cause of death in a 12-year-old diagnosed with epilepsy. J Paediatr Child Health 2004; 40:651-3. [PMID: 15469540 DOI: 10.1111/j.1440-1754.2004.00498.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Post-mortem investigation of sudden death in young people frequently reveals no overt cause for the death. Full investigation is hampered if tissue or blood is not retained for DNA analysis. We report a post mortem molecular diagnosis of long QT syndrome in a 12-year-old boy diagnosed with epilepsy who died suddenly playing sport. The DNA was extracted from an archived blood spot on his newborn screening ('Guthrie') card, which had been taken from him at 6 days of age. A missense mutation was detected in exon 5 of the KCNQ1 gene; R243C (835C > T), associated with long QT type 1. The same mutation was found in the mother (who now takes effective preventative therapy), but not in the sib who has now been reassured that she is not at risk of sudden death.
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Affiliation(s)
- J R Skinner
- Department of Paediatric Cardiology, Starship Hospital, Auckland, New Zealand.
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Sekoguchi E, Sato N, Yasui A, Fukada S, Nimura Y, Aburatani H, Ikeda K, Matsuura A. A novel mitochondrial carnitine-acylcarnitine translocase induced by partial hepatectomy and fasting. J Biol Chem 2003; 278:38796-802. [PMID: 12882971 DOI: 10.1074/jbc.m306372200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The carnitine-dependent transport of long-chain fatty acids is essential for fatty acid catabolism. In this system, the fatty acid moiety of acyl-CoA is transferred enzymatically to carnitine, and the resultant product, acylcarnitine, is imported into the mitochondrial matrix through a transporter named carnitine-acylcarnitine translocase (CACT). Here we report a novel mammalian protein homologous to CACT. The protein, designated as CACL (CACT-like), is localized to the mitochondria and has palmitoylcarnitine transporting activity. The tissue distribution of CACL is similar to that of CACT; both are expressed at a higher level in tissues using fatty acids as fuels, except in the brain, where only CACL is expressed. In addition, CACL is induced by partial hepatectomy or fasting. Thus, CACL may play an important role cooperatively with its homologue CACT in a stress-induced change of lipid metabolism, and may be specialized for the metabolism of a distinct class of fatty acids involved in brain function.
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Affiliation(s)
- Ei Sekoguchi
- Department of Geriatric Research, National Institute for Longevity Sciences, Obu, Aichi 474-8522, Japan
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Scaglia F, Scheuerle AE, Towbin JA, Armstrong DL, Sweetman L, Wong LJC. Neonatal presentation of ventricular tachycardia and a Reye-like syndrome episode associated with disturbed mitochondrial energy metabolism. BMC Pediatr 2002; 2:12. [PMID: 12507404 PMCID: PMC140035 DOI: 10.1186/1471-2431-2-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2002] [Accepted: 12/30/2002] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Hyperammonemia, hypoglycemia, hepatopathy, and ventricular tachycardia are common presenting features of carnitine-acylcarnitine translocase deficiency (Mendelian Inheritance in Man database: *212138), a mitochondrial fatty acid oxidation disorder with a lethal prognosis. These features have not been identified as the presenting features of mitochondrial cytopathy in the neonatal period. CASE PRESENTATION We describe an atypical presentation of mitochondrial cytopathy in a 2 day-old neonate. She presented with a Reye-like syndrome episode, premature ventricular contractions and ventricular tachycardia. Initial laboratory evaluation exhibited a large amount of 3-methylglutaconic acid on urine organic acid analysis, mild orotic aciduria and a nonspecific abnormal acylcarnitine profile. The evaluation for carnitine-acylcarnitine translocase deficiency and other fatty acid oxidation disorders was negative. The patient later developed a hypertrophic cardiomyopathy and continued to be affected by recurrent Reye-like syndrome episodes triggered by infections. A muscle biopsy exhibited signs of a mitochondrial cytopathy. During the course of her disease, her Reye-like syndrome episodes have subsided; however, cardiomyopathy has persisted along with fatigue and exercise intolerance. CONCLUSIONS This case illustrates that, in the neonatal period, hyperammonemia and ventricular tachycardia may be the presenting features of a lethal carnitine-acylcarnitine translocase deficiency or of a mitochondrial cytopathy, associated with a milder clinical course. This association broadens the spectrum of presenting phenotypes observed in patients with disturbed mitochondrial energy metabolism. Also, the presence of 3-methylglutaconic aciduria suggests mitochondrial dysfunction and mild orotic aciduria could potentially be used as a marker of mitochondrial disease.
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Affiliation(s)
- Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Angela E Scheuerle
- Department of Genetics, Teratology and Ethics Consulting, Dallas, TX, USA
- Texas Birth Defects Research Center, Dallas, TX, USA
| | - Jeffrey A Towbin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Dawna L Armstrong
- Department of Pathology, Baylor College of Medicine, Houston, TX, 77030, USA
| | | | - Lee-Jun C Wong
- Institute for Molecular and Human Genetics, Georgetown University Medical Center, Washington DC, 20007, USA
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Hsu BY, Iacobazzi V, Wang Z, Harvie H, Chalmers RA, Saudubray JM, Palmieri F, Ganguly A, Stanley CA. Aberrant mRNA splicing associated with coding region mutations in children with carnitine-acylcarnitine translocase deficiency. Mol Genet Metab 2001; 74:248-55. [PMID: 11592821 DOI: 10.1006/mgme.2001.3235] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This report describes three infants with genetic defects of carnitine-acylcarnitine translocase (CACT), an inner mitochondrial membrane carrier that is essential for long-chain fatty acid oxidation. Two of the patients were of European and Chinese origin; the third was from consanguineous Turkish parents. CACT activity was totally deficient in cultured skin fibroblasts from all three patients. Patient 1 was heterozygous for a paternal frameshift mutation (120 del T in exon 1) and a maternal lariat branch point mutation (-10 T --> G in intron 2). Patient 2 was heterozygous for the same lariat branch point (-10T --> G intron 2) mutation, derived from the father, and a maternal frameshift mutation (362 del G in exon 3). Patient 3 was homozygous for a frameshift mutation (306 del C in exon 3). All of the three frameshift mutations give rise to the same stop codon at amino acid residue 127 which is predicted to cause premature protein truncation. In addition, cDNA transcript analysis showed that these coding sequence mutations also increase the amount of aberrant mRNA splicing and exon skipping at distances up to 7.7 kb nucleotides from mutation sites. The data suggest that the stability of mRNA transcripts is decreased or the frequency of aberrant splicing is increased in the presence of CACT coding sequence mutations. These results confirm that CACT is the genetic locus of the recessive mutations responsible for the fatal defects of fatty acid metabolism previously associated with deficiency of translocase activity in these three cases.
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Affiliation(s)
- B Y Hsu
- Division of Endocrinology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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Albers S, Marsden D, Quackenbush E, Stark AR, Levy HL, Irons M. Detection of neonatal carnitine palmitoyltransferase II deficiency by expanded newborn screening with tandem mass spectrometry. Pediatrics 2001; 107:E103. [PMID: 11389301 DOI: 10.1542/peds.107.6.e103] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The introduction of tandem mass spectrometry to newborn screening has substantially expanded our ability to diagnose metabolic diseases in the newborn period. We report the first case of neonatal carnitine palmitoyltransferase deficiency II detected by expanded newborn screening with tandem mass spectrometry. The neonate presented with dysmorphic facial features, structural malformations, renal failure, seizures, and cardiac arrythmias and died on the third day of life. This experience illustrates the importance of expanded newborn screening to avoid missing a metabolic diagnosis in early infantile death.
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Affiliation(s)
- S Albers
- Division of Genetics, Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.
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