Malonyl-CoA, a product of acetyl-CoA carboxylase is a metabolic intermediate in lipogenic tissues that include liver and adipose tissue, where it is involved in the de novo fatty acid synthesis and elongation. Malonyl-CoA decarboxylase (MLYCD, E.C.4.1.1.9), a 55-kDa enzyme catalyses the conversion of malonyl-CoA to acetyl-CoA and carbon dioxide, thus providing a route for disposal of malonyl-CoA from mitochondria and peroxisomes, whereas in the cytosol, the malonyl-CoA pool is regulated by the balance of MLYCD and acetyl-CoA carboxylase activities. So far, 34 cases with different MLYCD gene defects comprising point mutations, stop codons, and frameshift mutations have been reported in the literature. Here, we describe the follow-up of a patient affected by malonic aciduria upon neonatal onset. Molecular analysis showed novel homozygous mutations in the MLYCD gene. Our findings expand the number of reported cases and add a novel variant to the repertoire of MLYCD mutations.
<b><i>Introduction:</i></b> Neuronal ceroid lipofuscinoses (NCLs) are a broad class of inherited lysosomal storage disorders. Known mutations in at least 13 different genes can result in NCL with variable ages of onset, symptoms, and pathologic findings. Generally, these patients experience cognitive and motor decline, seizures, visual impairment, and premature death. Pathologically, NCL patients display heterogeneous histologic abnormalities, but consistently exhibit neuronal loss, reactive gliosis, and lysosomal accumulation of autofluorescent storage material or lipopigment. Juvenile-onset NCL has been classically referred to as Batten disease. By far the most prevalent NCL is <i>CLN3</i>-associated disease. It is an autosomal recessive condition that is usually caused by mutations in the ceroid-lipofuscinosis, neuronal 3 (<i>CLN3</i>) gene. <i>CLN3</i> encodes battenin, a ubiquitously expressed transmembrane protein of unknown function that is associated with cellular homeostasis and neuronal survival. The initial clinical symptom of <i>CLN3</i>-associated NCL is central vision loss, which is usually detected between 4 and 9 years of age. Seizures typically begin early in the second decade of life, and affected individuals rarely live beyond their mid-20ies. <b><i>Case Presentation:</i></b> Herein, we describe a 16-year-old patient with <i>CLN3-</i>related juvenile NCL with a preliminary diagnosis of Niemann Pick Type C disease. The proband showed characteristic clinical signs, including epilepsy, ataxia, psychomotor regression, dementia, and visual impairment with an unusual elevation of lyso-sphingomyelin-509 (LysoSM-509; 812 nmol/L, normal 1–33 nmol/L). A homozygous NM_001042432.2(CLN3):c.233dup (p.Thr80fs) variant was detected at exon 4 of <i>CLN3.</i> Diagnosis of NCL was difficult due to the pronounced elevation of LysoSM-509. <b><i>Discussion:</i></b> LysoSM-509 is a biomarker which is elevated especially in Niemann Pick Type C. We can consider that a high LysoSM-509 level might be also an indicator of NCL, especially NCL type 3.
<b><i>Introductıon:</i></b> Succinate dehydrogenase deficiency, also known as mitochondrial complex II deficiency, is a rare inborn error of metabolism, accounting for approximately 2% of mitochondrial disease. Mutations in the four genes <i>SDHA, B, C,</i>and <i>D</i> have been reported resulting in diverse clinical presentations. The vast majority of clinically affected individuals reported in the literature harbor genetic variants within the <i>SDHA</i> gene and present with a Leigh syndrome phenotype, clinically defined as a subacute necrotizing encephalopathy. <b><i>Case Report:</i></b> Herein, we report the first case of a 7-year-old child who was diagnosed as having succinate dehydrogenase deficiency. The affected child presented at 1 year of age with encephalopathy and developmental regression following viral illnesses. MRI changes supported a clinical diagnosis of Leigh syndrome and c.1328C>Q and c.872A>C <i>SDHA</i> variants were identified as compound heterozygous. Mitochondrial cocktail treatment including L-carnitine, riboflavin, thiamine, biotin, and ubiquinone was started. Mild clinical improvement was observed after treatment. He is now unable to walk and speak. The second patient, a 21-year-old woman, presented with generalized muscle weakness, easy fatigability, and cardiomyopathy. Investigations revealed increased lactate level of 67.4 mg/dL (4.5–19.8) with repeatedly increased plasma alanine levels 1,272 µmol/L (200–579). We administered carnitine, coenzyme, riboflavin, and thiamine for empirical therapy with the suspicion of mitochondrial disease. Clinical exome sequencing revealed compound heterozygous variants NM_004168.4:c.1945_1946del (p.Leu649GlufsTer4) at exon 15 of the <i>SDHA</i> gene and NM_004168.4:c.1909-12_1909-11del at intron 14 of <i>SDHA</i> gene. <b><i>Discussion and Conclusion:</i></b> There are several very different presentations including Leigh syndrome, epileptic encephalopathy, and cardiomyopathy. Some cases present following viral illness; this feature is not specific to mitochondrial complex II deficiency and occurs in many other mitochondrial disease presentations. There is no cure for complex II deficiency, though some reported patients showed clinical improvement following riboflavin therapy. Riboflavin is not the only therapeutic intervention that is available to patients with an isolated complex II deficiency and various other compounds have shown promise in the treatment of symptoms, including L-carnitine and ubiquinone. Treatment alternatives such as parabenzoquinone EPI-743 and rapamycin are under study in the treatment of the disease.
Objectives Congenital disorders of glycosylation (CDGs) are rare inherited metabolic disorders associated with facial dysmorphism and in the majority of the patients, there is an important neurological impairment. Epilepsy was a main concern in rare forms of the disease. There are two groups of the disease: CDG-I results from the defects in glycan addition to the N-terminal and CDG-II occurs due to defects in the processing of protein bound glycans. SLC35A2-CDG is a rare form of CDG caused by mutations in the X-linked gene that encodes a UDP-Galactose transporter. The manifestations of the disease include seizures, failure to thrive, delayed myelination, and cerebral atrophy. Case presentation We describe herein a severe female child with intractable seizures, microcephaly, growth retardation, hypotonia, global developmental delay, facial dysmorphism, skeletal findings, cerebral/cerebellar atrophy, and thin corpus callosum, and a mildly affected male carrying a novel variant with seizures and mild global developmental delay who were found by whole exome sequencing (WES) for SLC35A2 mutations previously not reported. Conclusions Our findings expand the number of reported cases and add novel variants to the repertoire of SLC35A2-CDG.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.