Background. X-linked adrenoleukodystrophy (X-ALD) is a progressive genetic disorder affecting the metabolism of very long chain fatty acids in the adrenal glands, spinal cord and white matter of the nervous system. It is an inherited metabolic storage disease whereby a defect in a specific enzyme results in the accumulation of very long-chain fatty acids (VLCFA) that are harmful to some cells and organs. VLCFA analysis for confirmation of X-linked adrenoleukodystrophy is one of the most requested tests among the send-out laboratory services of the Biochemical Genetics Laboratory at the Institute of Human Genetics. This paper aims to review the clinical characteristics and the results of the VLCFA analysis of the patients whose samples we received for testing.Methods. Overseas tests samples received by the Biochemical Genetics Laboratory for VLCFA from 2002-2016 were included. The details of the patients were collated in an overseas tests database and was the main source of the data for this study. The results of the VLCFA tests sent to the Kennedy Krieger Institute and The Children’s Hospital at Westmead were inputted into the said database. Descriptive statistics was utilized in order to examine the clinical and biochemical data of the patients.Results. The results showed that out of the 54 samples submitted to our laboratory, 19 (35%) of the samples received from male patients suspected to have X-ALD yielded positive results and another 10 (19%) females were found to be carriers. Visual defect followed by deteriorating mental status were the most frequent indications for VLCFA testing. Conclusion. Having a significant diagnostic yield of 54%, early diagnosis of X-linked adrenoleukodystrophy in our population is important so that proper management that could prevent the progression of the disease could be timely instituted.
Metabolism, Inborn Errors ; Peroxisomal Disorders ; Adrenoleukodystrophy

Peroxisomes are subcellular organells catalyzing a number of important functions in cellular metabolism. Their functions are mostly related to lipid metabolism. Genetic disorders of peroxisomes are divided into 2 categories: peroxisomal biogenesis disorders and single peroxisomal enzyme deficiencies. This paper describes an overview of the peroxisomal disorders, including metabolic basis, and clinical and laboratory findings.
Lipid Metabolism ; Metabolism ; Peroxisomal Disorders* ; Peroxisomes ; Organelle Biogenesis

We describe below a case of Zellweger syndrome case with facial dysmorphism, profound hypotonia, and hepatomegaly. He died at the age of 2 months. Zellweger syndrome is a disease marked by the absence of hepatic and renal peroxisomes. Because peroxisomes have many vital anabolic and catabolic functions within the cell, their absence results in profound cellular dysfunction. A biochemical study of plasma revealed elevation of very long chains of fatty acids and pipecolic acid, consistent with peroxisomal disorder. The cultured skin fibroblasts showed a marked decrease in plasmalogen synthesis enzyme : dihydroxyacetonephosphate acyl transferase(DHAP-AT) The clinical characteristics and biochemical findings led to the diagnosis of Zellweger syndrome. The pattern of inheritance is autosomal recessive, hence genetic counseling can help the families. In infantile hypotonia patients with unknown cause, peroxisomal disorder should be included in the differential diagnosis. We report the first confirmed case of Zellweger syndrome by enzyme assay in Korea.
Cell Culture Techniques ; Diagnosis ; Diagnosis, Differential ; Enzyme Assays ; Fatty Acids ; Fibroblasts ; Genetic Counseling ; Hepatomegaly ; Humans ; Infant, Newborn ; Korea* ; Muscle Hypotonia ; Peroxisomal Disorders ; Peroxisomes ; Plasma ; Skin ; Wills ; Zellweger Syndrome*

Neonatal adrenoleukodystrophy(NALD) is an inherited autosomal recessive disease characterized by very early onset of neurologic deterioration, extreme hypotonia, poor sucking reflex, failure to thrive, poor or absent grasp and Moro reflexes, diminished deep tendon reflexes, neonatal seizure refractory to antiepileptic drugs, progressive hepatomegaly, and mild or absent craniofacial dysmorphism. In the peroxisomal biogenesis disorders, whose basic defect are the incapabilities to import one or more proteins into the organelle, include Zellweger syndrome(ZS), NALD, and infantile Refsum disease(IRD). These are now thought to represent a continuous spectrum of disease severity, ZS the most severe, IRD the least severe, and NALD intermediate. Furthermore, their biochemistry and microscopic pathology are nearly identical. The biochemical abnormalities of NALD are the elevated levels of very long chain fatty acid(VLCFA), phytanic acid, pristanic acid, pipecolic acid in plasma, cultured skin fibroblasts, and reduced plasmalogen contents in erythrocytes. There are no effective treatments until now. We experienced an one day old neonate with hypotonia and seizure, who was diagnosed as NALD by elevated plasma VLCFA. So we report the case with a brief review of literature.
Anticonvulsants ; Biochemistry ; Organelle Biogenesis ; Erythrocytes ; Failure to Thrive ; Fibroblasts ; Hand Strength ; Hepatomegaly ; Humans ; Infant, Newborn ; Muscle Hypotonia ; Organelles ; Pathology ; Peroxisomal Disorders* ; Phytanic Acid ; Plasma ; Reflex ; Reflex, Stretch ; Seizures* ; Skin

Diseases of inborn errors of metabolism (IEMs) are very rare but the overall prevalence of IEMs is not low, and in the United States, about 5~10% of admitted patients have some genetic predispositions. Clinical manifestations of IEMs are very diverse, but most frequent manifestations are neurological symptoms and signs. IEMs in Korea have been underestimated because of prejudice, underdevelopment of diagnostic tools and ignorance. The Korean Pediatric Society has done a retrospective study in order to know the relative incidence of IEMs in 2001. All hospitals with over 100 beds participated in the study. The most frequent disease was Wilson disease (201 cases for 10 years) followed by phenylketonuria (98 cases for 10 years) and Hunters disease (69 cases for 10 years). Disorders of mineral metabolism were the most frequently diagnosed disease groups (252 cases for 10 years) followed by organic acidopathies (220 cases), aminoacidopathies (139 cases), mucopolysaccharidosis (131 cases), disorders of carbohydrate metabolism (84 cases), sphingolipidosis (69 cases), urea cycle disorders (39 cases), peroxisomal disorders (27 cases), porphyrias (16 cases), disorders of purine and pyrimidine metabolism (14 cases), disorders of membrane transport (13 cases), fatty acid oxidation disorders (9 cases), oligosaccharidosis (2 cases), and mucolipidosis (1 case). Clearly, Koreans are not protected from IEMs and a systematic approach is needed to make diagnosis more easy and accurate.
Brain Diseases, Metabolic, Inborn ; Carbohydrate Metabolism ; Diagnosis ; Genetic Predisposition to Disease ; Hepatolenticular Degeneration ; Humans ; Incidence ; Korea* ; Membranes ; Metabolism ; Metabolism, Inborn Errors* ; Mucolipidoses ; Mucopolysaccharidoses ; Peroxisomal Disorders ; Phenylketonurias ; Porphyrias ; Prejudice ; Prevalence ; Retrospective Studies ; Sphingolipidoses ; United States ; Urea Cycle Disorders, Inborn

Adrenomyeloneuropathy (AMN), one of the variants of X-linked adrenoleukodystrophy (ALD), is inherited peroxisomal disorder associated with the accumulation of very long chain fatty acids (VLCFA). AMN is characterized primarily by involvements of long ascending and descending tracts of the spinal cord and peripheral neuropathy, which leads to spastic paraparesis and urinary and erectile dysfunction. We experienced the AMN case of a 33-year-old man presenting bilateral progressive spastic paraparesis, impotence and urge incontinence with primary adrenal failures, as confirmed by increased serum of VLCFA concentrations. Considering that somatosensory evoked potentials in posterior tibial nerve was the only abnormal finding in electrophysiologic findings when compared with the severe spastic gait pattern shown, it is necessary to follow up with electrophysiologic studies.
Adrenal Insufficiency ; Adrenoleukodystrophy ; Erectile Dysfunction ; Evoked Potentials, Somatosensory ; Fatty Acids ; Gait Disorders, Neurologic ; Male ; Paraparesis, Spastic ; Peripheral Nervous System Diseases ; Peroxisomal Disorders ; Spinal Cord ; Tibial Nerve ; Urinary Incontinence, Urge

X-linked adrenoleukodystrophy (X-ALD) is a rare peroxisomal disorder, that is rapidly progressive, neurodegenerative, and recessive, and characteristically primary affects the central nervous system white matter and the adrenal cortex. X-ALD is diagnosed basaed on clinical, radiological, and serological parameters, including elevated plasma levels of very long chain fatty acids (VLCFA), such as C24:0 and C26:0, and high C24:0/C22:0 and C26:0/C22:0 ratios. These tests are complemented with genetic analyses. A 7.5-year-old boy was admitted to Department of Pediatrics, Chungnam National University Hospital with progressive weakness of the bilateral lower extremities. Brain magnetic resonance imaging confirmed clinically suspected ALD. A low dose adrenocorticotropic hormone stimulation test revealed parital adrenal insufficiency. His fasting plasma levels of VLCFA showed that his C24:0/C22:0 and C26:0/C22:0 ratios were significantly elevated to 1.609 (normal, 0-1.390) and 0.075 (normal, 0-0.023), respectively. Genomic DNA was extracted from peripheral whole blood samples collected from the patient and his family. All exons of ABCD1 gene were amplified by polymerase chain reaction (PCR) using specific primers. Amplified PCR products were sequenced using the same primer pairs according to the manufacturer's instructions. We identified a missense mutation (p.Arg163Leu) in the ABCD1 gene of the proband caused by the nucleotide change 488G>T in exon 1. His asymptomatic mother carried the same mutation. We have reported an unpublished mutation in the ABCD1 gene in a patient with X-ALD, who showed increased ratio of C24:0/C22:0 and C26:0/C22:0, despite a normal VLCFA concentrations.
Adrenal Cortex ; Adrenal Insufficiency ; Adrenocorticotropic Hormone ; Adrenoleukodystrophy* ; Brain ; Central Nervous System ; Chungcheongnam-do ; Complement System Proteins ; DNA ; Exons ; Fasting ; Fatty Acids ; Humans ; Lower Extremity ; Magnetic Resonance Imaging ; Male ; Mothers ; Mutation, Missense ; Pediatrics ; Peroxisomal Disorders ; Plasma ; Polymerase Chain Reaction

INTRODUCTIONPeroxisomal disorders are subdivided into peroxisome biogenesis disorders (PBDs) and single peroxisomal enzyme deficiency. Many peroxisomal diseases exhibit excessive oxidative stress, leading to neurological alterations and dysfunction. Peroxisomes use oxygen in oxidative reactions that generate hydrogen peroxide. This study aimed to investigate various oxidative stress parameters in patients suffering from peroxisomal disorders.

METHODSA total of 20 patients with peroxisomal disorders, aged six months to 13 years (mean age 5.9 ± 3.2 years), were compared to 14 healthy controls. All individuals were subjected to full history-taking, including a three-generation pedigree analysis concerning parental consanguinity and similarly affected members in the family, with meticulous clinical examination to detect any malformation or anomaly. Estimation of very-long-chain fatty acids and phytanic acid was done to verify the diagnosis. Brain magnetic resonance imaging, electroencephalogram, visual evoked potential, auditory potential and plain radiography were conducted to assess the pathological condition of the patients. Oxidative stress parameters, including nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD), were estimated in both the patients and controls.

RESULTSSignificant increases in both MDA and NO were found in patients with PBDs. It was also demonstrated that SOD was significantly lower in patients with PDB than the controls.

CONCLUSIONThis study sheds more light on the link between oxidative stress and peroxisomal disorders, as oxidative stress may be a hallmark of peroxisomal disorders. Consequently, one of the useful neuronal rescue strategies could be treatment with antioxidant agents in addition to other lines of treatments.

Adolescent ; Biomarkers ; blood ; Case-Control Studies ; Child ; Child, Preschool ; Consanguinity ; Egypt ; Humans ; Infant ; Malondialdehyde ; blood ; Matched-Pair Analysis ; Nitric Oxide ; blood ; Oxidative Stress ; genetics ; Pedigree ; Peroxisomal Disorders ; blood ; genetics ; physiopathology ; Superoxide Dismutase ; blood