aminoacidopathy

BACKGROUND: Classical homocystinuria (HCU) is an autosomal recessive inborn error of metabolism, which is caused by the cystathionine-β-synthase (CBS: encoded by CBS ) deficiency. Symptoms of untreated classical HCU patients include intellectual disability (ID), ectopia lentis and long limbs, along with elevated plasma methionine, and homocysteine. METHODS: A total of 429 ID patients (age range: 1.6-23 years) were sampled from Northern areas of Punjab, Pakistan...

To analyze the screening results for inherited metabolic disorders (IMD) in newborns by tandem mass spectrometry (MS/MS) in Guangzhou.A total of 272 117 newborns in Guangzhou from Jan 2015 to Dec 2020 were screened for IMD by MS/MS in Guangzhou Newborn Screening Center. When the primary screening was positive, the newborns and their mothers were recalled. For those with positive in re-examination, the biochemical and related genetic analysis were required for confirmation. The screening results, clinical characteristics and outcomes of the confirmed cases were retrospectively analyzed and the performance was optimized...

There is broad consensus on the health benefits that neonatal screening has provided in Spain, since Professor Mayor Zaragoza began his research project for the early detection of phenylketonuria and other aminoacidopathies in 1968, to date. In these decades there has been a great evolution and development of Neonatal Screening Programs (NSP) in Spain. This paper presents the effect on the development of the NSPs of the decentralization of Public Health responsibilities in the Autonomous Communities, creating differences among them by atomizing the decisions on the expansion of the diseases to be screened...

OBJECTIVE: Tandem mass spectrometry (MS/MS) is being used for newborn screening since this laboratory testing technology increases the number of metabolic disorders that can be detected from dried blood-spot specimens. In the Community of Madrid, it was implemented in March 2011 and it includes 13 aminoacidopathies, fatty acid oxidation disorders and organic acidemias. The aim of this study was to describe our experience and evaluate the screening positive cases in a period of 9 years (2011-2019)...

OBJECTIVE: The main justification of this study was to describe our experience in neonatal screening and to define the prevalence of the diseases included in the neonatal screening program in Andalusia, among which are congenital hypothyroidism, expanded screening (aminoacidopathies, mitochondrial beta-oxidation defects and organic acidurias), cystic fibrosis, and screening for sickle cell anemia. METHODS: The study was carried out in the Metabolopathies Unit of the Virgen del Rocío Hospital in Seville with samples of newborns from Western Andalusia (Cádiz, Córdoba, Huelva and Seville) and autonomous city of Ceuta...

INTRODUCTION: In the last two decades, the introduction of tandem mass spectrometry in clinical laboratories has enabled simultaneous testing of numerous acylcarnitines and amino acids from dried blood spots for detecting many aminoacidopathies, organic acidurias and fatty acid oxidation disorders. The expanded newborn screening was introduced in Slovenia in September 2018. Seventeen metabolic diseases have been added to the pre-existing screening panel for congenital hypothyroidism and phenylketonuria, and the newborn screening program was substantially reorganized and upgraded...

Nonketotic hyperglycinemia (NKH) is an autosomal recessive disorder caused by a defect in glycine cleavage enzyme. It leads to the accumulation of glycine in the body tissues, blood, and cerebrospinal fluid (CSF). Most NKH cases are diagnosed during the natal period of life and are fatal if not promptly diagnosed and managed. Here we present a case of a two-day-old child who presented with reluctant feeding and lethargy. She had reduced tone in all four limbs and a Glasgow Coma Scale score of 9. Keeping an infectious etiology in mind, she was started on cefotaxime and amikacin...

BACKGROUND: Maple syrup urine disease is a rare autosomal-recessive aminoacidopathy, caused by deficient branched-chain 2-keto acid dehydrogenase (BCKD), with subsequent accumulation of branched-chain amino acids (BCAAs): leucine, isoleucine and valine. While most cases of MSUD are classic, some 20% of cases are non-classic variants, designated as intermediate- or intermittent-types. Patients with the latter form usually develop normally and are cognitively intact, with normal BCAA levels when asymptomatic...

Background and Objectives: There is a paucity of information on the use of complementary and alternative medicine (CAM) in patients with inborn errors of metabolism (IEM). This study's objective was to evaluate the self-reported use and perceived effectiveness of CAM in adults and children with IEM. Methods: Patients aged 0-70 years and caregivers seen at the London Health Sciences Centre Metabolic Clinic (London, Ontario, Canada) between July 2017 and August 2017 were recruited to complete a questionnaire regarding CAM use to help their IEM diagnosis and perceived effectiveness of these therapies...

OBJECTIVE: To determine the pattern of various inherited metabolic disorders specifically through plasma amino acid and urine organic acid testing in high-risk paediatric population.. METHODS: The cross-sectional retrospective study was conducted at the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, and comprised data from April 2015 to March 2018 of children referred to the Department of Chemical Pathology and Endocrinology for work-up of suspected inherited metabolic disorders...

The establishment of expanded newborn screening (NBS) not only results in the early diagnosis and treatment of neonates with inborn errors of intermediary metabolism disorders (IEMDs) but also helps the affected females to reach the reproductive age under medical and dietetic support, as well as to give birth to normal infants. In this review, we aimed to focus on laboratory investigation tests, dietetic management and medical support for most known IEMD pregnant and lactating women, such as those suffering from aminoacidopathies, carbohydrate metabolic diseases and fatty acid (FAO) oxidation disorders...

Inborn errors of metabolism (IEMs) are rare group of genetic disorders comprising of more than 1,000 different types. Around 200 of IEMs are potentially treatable through diet, pharmacological and other therapies, if diagnosed earlier in life. IEMs can be diagnosed early through newborn screening (NBS) programs, which are in place in most of the developed countries. However, establishing a NBS in a developing country is a challenging task due to scarcity of disease related data, large population size, poor economy, and burden of other common disorders...

Maple syrup urine disease is the primary aminoacidopathy affecting branched-chain amino acid (BCAA) metabolism. The disease is mainly caused by the deficiency of an enzyme named branched-chained α-keto acid dehydrogenase (BCKD), which consist of four subunits (E1α, E1β, E2, and E3), and encoded by BCKDHA, BCKDHB, DBT, and DLD gene respectively. BCKD is the main enzyme in the catabolism pathway of BCAAs. Hight rate of autosomal recessive disorders is expected from consanguineous populations like Iran. In this study, we selected two sets of STR markers linked to the four genes, that mutation in which can result in MSUD disease...

Amino acid catabolism is frequently executed in mitochondria; however, it is largely unknown how aberrant amino acid metabolism affects mitochondria. Here we report the requirement for mitochondrial saccharopine degradation in mitochondrial homeostasis and animal development. In Caenorhbditis elegans , mutations in the saccharopine dehydrogenase (SDH) domain of the bi-functional enzyme α-aminoadipic semialdehyde synthase AASS-1 greatly elevate the lysine catabolic intermediate saccharopine, which causes mitochondrial damage by disrupting mitochondrial dynamics, leading to reduced adult animal growth...

The use of specialized centers has been the main alternative for an appropriate diagnosis, management and follow up of patients affected by inborn errors of metabolism (IEM). These centers facilitate the training of different professionals, as well as the research at basic, translational and clinical levels. Nevertheless, few reports have described the experience of these centers and their local and/or global impact in the study of IEM. In this paper, we describe the experience of a Colombian reference center for the research, diagnosis, training and education on IEM...

Phenylketonuria (PKU) is an autosomal recessive disorder caused by the deficiency of phenylalanine hydroxylase enzyme that catalyzes the conversion of L-phenylalanine to L-tyrosine using tetrahydrobiopterin (BH4) as a cofactor. Among aminoacidopathies, PKU is one of the most prevalent disorders in different populations. It may be caused by deficiency of BH4 or mutations in PAH. About 98% of PKU patients have mutations in the PAH, while the remaining have BH4 deficiency. If PKU is diagnosed earlier in life using advance analytical techniques (e...

The neuropathological effects of phenylketonuria (PKU) stem from the inability of the body to metabolize excess phenylalanine (Phe), resulting in accumulation of Phe in the blood and brain. Since the kidney normally reabsorbs circulating amino acids with high efficiency, we hypothesized that preventing the renal uptake of Phe might provide a disposal pathway that could lower systemic Phe levels. SLC6A19 is a neutral amino acid transporter responsible for absorption of the majority of free Phe in the small intestine and reuptake of Phe by renal proximal tubule cells...

Although individual cases of inherited metabolic disorders are rare, overall they account for a substantial number of disorders affecting the central nervous system. Organic acidemias and aminoacidopathies include a variety of inborn errors of metabolism that are caused by defects in the intermediary metabolic pathways of carbohydrates, amino acids, and fatty acid oxidation. These defects can lead to the abnormal accumulation of organic acids and amino acids in multiple organs, including the brain. Early diagnosis is mandatory to initiate therapy and prevent permanent long-term neurologic impairments or death...

OBJECTIVES: To ascertain the proportion of neonates and infants presenting with suspicion of an inborn error of metabolism in the centers identified by ICMR for newborn screening. METHODS: A set of red flag signs suggestive IEM were listed by the Taskforce members. The age group was limited to one year as it was understood that most of the small molecules with a severe phenotype would present before the age of one year. Further investigations were tandem mass spectrometry, gas chromatography mass spectrometry and high performance liquid chromatography...

Homocystinuria is the second most common treatable aminoacidopathy. Clinically, affected patients present with eye, skeleton, central nervous system, and most importantly, vascular system abnormalities. This autosomal recessive disorder leads to accumulation of homocysteine and its metabolites in the blood and urine. In this report, we present a case with clinical and biochemical findings of homocystinuria with stroke and a positive familial history of the disease in her brother. A 4-year-old girl was admitted to pediatric emergency ward because of acute onset of right hemiparesis and subsequent generalized tonic-clonic seizures...