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Carrier Screening For Inherited Genetic Conditions
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Whitney Bender, Lorraine Dugoff
Currently 19 diseases are available for screening on Jewish genetic disease panels. In addition to those mentioned previously, the following diseases are included: maple syrup urine disease, glycogen storage disease type 1a, dihydrolipoamide dehydrogenase (DLD) deficiency, familial hyperinsulinism, Joubert syndrome, nemaline myopathy, SMA, Usher syndrome type 1F, Usher syndrome type III, and Walker-Warburg syndrome [37].
Deficiency of the pyruvate dehydrogenase complex
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
The pyruvate dehydrogenase complex (PDHC) is a mitochondrial multienzyme system that catalyzes the oxidation of pyruvate to CO2 and acetylCoA and concomitantly generates reduced nicotinamideadenine-dinucleotide (NADH) (Figure 50.1) [1]. Cofactors include thiaminepyrophosphate (TPP), lipoic acid, coenzyme A (CoA), flavineadeninedinucleotide (FAD), and nicotinamideadeninedinucleotide (NAD1); Mg is required. There are eight different protein components, in seven of which human deficiency disease has been documented. The three basic components E1 (pyruvate dehydrogenase, PDH) E2 (dihydrolipoamide acetyltransferase) and E3 (dihydrolipoamide dehydrogenase) are functional catalytic proteins, of types that are shared by all oxoacid dehydrogenases. There are two regulatory components, E1kinase and phospho-E1-phosphatase with thiamine pyrophosphate (TPP) as a cofactor.
Immunopathogenesis of Vanishing Bile Duct Syndromes
Published in Gianfranco Alpini, Domenico Alvaro, Marco Marzioni, Gene LeSage, Nicholas LaRusso, The Pathophysiology of Biliary Epithelia, 2020
John M. Vierling, Marius Braun, Haimei Wang
AMAs (primarily comprised of IgM with substantial quantities of IgA, IgGl and IgG3 isotypes) are present in the sera of >95% of patients with PBC and react with antigens of the 2-oxoacid dehydrogenase complex located in the matrix associated with the inner mitochondrial membrane.59,63 Autoantigens include the E2 subunits of the pyruvate dehydrogenase complex (PDC-E2), branched chain 2-oxoacid dehydrogenase complex (BCOADC-E2), 2-oxoglutarate dehydrogenase complex (OGDC-E2), dihydrolipoamide dehydrogenase binding protein (E3BP) and the E1α subunit of PDC. AMAs reactive with PDC-E2, OGDC-E2 and BCOADC-E2 recognize conformational epitopes with aa motifs of ETDKA, ETDK(T) and (GlnS)DKA with lipoic acid covalendy bound to the ε group of lysine (K). However, lipoic acid is not required for antigenicity, and PDC-E1α lacks a lipoyl domain. AMAs and PDC-E2, BCOADC-E2 and OGDC-E2 autoantigens are also present in bile and saliva, where secretory IgA is the dominant isotype.64–66
Targeting glucose metabolism to develop anticancer treatments and therapeutic patents
Published in Expert Opinion on Therapeutic Patents, 2022
Yan Zhou, Yizhen Guo, Kin Yip Tam
Pyruvate dehydrogenase complex (PDC) is a 9.5 million Da multi-enzyme complex located in mitochondrial matrix and consisting of four major enzyme components: pyruvate dehydrogenase (E1), dihydrolipoyl transacetylase (E2), dihydrolipoamide dehydrogenase (E3), and E3-binding protein (E3BP), as well as the two kinds of dedicated regulatory enzymes: PDKs and pyruvate dehydrogenase phosphatase [47]. The detailed structure and function of PDC have been well reviewed [48]. As an important gatekeeper enzyme that links pyruvate to the TCA cycle, PDC catalyzes the conversion of pyruvate to acetyl-CoA coupled with the reduction of NAD+ to NADH. The modulation of PDC activities depends on the reversible phosphorylation and dephosphorylation [49]. Phosphorylation of E1α component, regardless of which one of the three serine residues, is enough to switch off PDC activity. Thus, phosphorylation of PDC by PDKs will downregulate its activity, and subsequently reduce the flux of pyruvate into the TCA cycle. In human, phosphorylation of PDC is catalyzed by any of four isoforms of pyruvate dehydrogenase kinase (PDK1-4) which are expressed differently in specific tissues. In particular, PDK1 is closely associated with cancer malignancy and serves as the only PDK isoform that could phosphorylate all serine sites of PDC [50]. To sum up, inhibiting PDKs has been one of the recognized strategies to fight against cancer by increasing OXPHOS and reversing Warburg effect.
EEG Pattern in Neonatal Maple Syrup Urine Disease: Description and Clinical Significance
Published in The Neurodiagnostic Journal, 2021
Rajesh P. Poothrikovil, Khalid Al Thihli, Amna Al Futaisi
Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder characterized by deficiency of branched-chain keto acid dehydrogenase complex, which is required to metabolize the three branched chain amino acids (BCAAs) leucine, isoleucine and valine. This deficiency leads to an abnormal accumulation of BCAAs and their toxic byproducts, namely alpha-ketoacids, typically detectable in the blood and urine. MSUD is thus one of the main organic acidurias, a group of disorders characterized by the excretion of non-amino organic acids in urine (Clague and Thomas 2002). During the neonatal period, this metabolic dysfunction results in progressive encephalopathy with symptoms of lethargy, vomiting, posturing and abnormal movements in neonates; the classic form of the disease. If untreated, progressive brain damage causes coma, seizures and death usually within a few weeks (Seashore 2009). The major clinical features of MSUD are delayed psychomotor development, feeding difficulties and a characteristic odor of maple syrup which can be detected in the urine (Papetti et al. 2013). Currently, there are five types of MSUD: classic, intermediate, intermittent, thiamine responsive and dihydrolipoamide dehydrogenase deficient (Seashore 2009). These classifications are based on the severity of the disease, age of onset, response to thiamine therapy and the affected gene locus. All forms are inherited as autosomal recessive traits. Imaging in classic MSUD patients may show brain edema affecting the myelinated white matter, thalami and globi pallidi (Poretti et al. 2013)
Update on the proteomics of male infertility: A systematic review
Published in Arab Journal of Urology, 2018
Manesh Kumar Panner Selvam, Ashok Agarwal
Extensive research has been carried out at our laboratory to decipher the role of DEPs in patients with both unilateral and bilateral varicocele. All these proteins were involved in spermatogenesis, mitochondrial dysfunction, energy metabolism, and acrosome reaction [48–51]. Comparative proteomic analysis identified 58 DEPs in bilateral varicocele [48] and 38 proteins were unique in patients with unilateral varicocele [50]. Another study comparing patients with unilateral and bilateral varicocele predicted glutathione S-transferase mu 3 (GSTM3), sperm protein associated with the nucleus, X chromosome, family member B1 (SPANXB1), Parkinson disease protein 7 (PARK7), proteasome subunit α8 (PSMA8), dihydrolipoamide dehydrogenase (DLD), SEMG1, and SEMG2 as potential biomarkers to differentiate unilateral from bilateral varicocele [48]. Network and pathway analysis was able to show that 87% of the DEPs involved in major energy metabolism were associated with mitochondrial dysfunction [48]. A list of potential biomarkers in different varicocele conditions is provided in Table 2 [13,41,48,49,66,80].