Inherited Errors Of Metabolism Research Articles

Epidemiological Assessment of a Pediatric Palliative Care Clinic at a Brazilian Quaternary Hospital: 20 Years of Experience.

Background: The pediatric palliative care (PPC) sets up an interdisciplinary approach of chronic complex diseases throughout birth to adolescence. It encompasses countless contrasts in development and diagnosis scopes, which make this area a challenge to nonpediatric practitioners. Objective: We sought to assess the most prevalent diseases in follow-up of the PPC team. Methods: We analyzed the medical records of PPC clinic during the years 2001 and 2021 and the diagnosis of outpatients. We established a parallel with the world scientific literature concerning the epidemiology of PPC. Results: The most prevalent diseases were epidermolysis bullosa (36.9%), followed by neurological Inherited Errors of Metabolism (IEM) diseases (19.0%), IEM diseases (14.3%), dysmorphological and chromosomal disorders (8.5%), skeletal disorders mainly osteogenesis imperfecta (6.9%), and liver transplantation conditions (5.5%) (p < 0.001). The less frequent conditions were external causes, such as neonatal insults or traffic accidents (2.8%), cancer (1.7%), congenital cardiopathies (1.4%), congenital infectious diseases (1.1%), gastrointestinal and hepatic conditions (0.8%), and rheumatological conditions (0.3%). The patients were older at diagnosis (6.9 years) and at PPC referral (13.2 years) than patients with epidermolysis bullosa and skeletal disorders and dysmorphological and chromosomal disorders were younger on referral. Conclusion: There are a lot of complex chronic conditions which could benefit from palliative care in pediatric setting. However, epidemiological and symptomatological assessment of the health service is necessary to provide an appropriate care to the country's reality.

Nutrition, Microbiota and Role of Gut-Brain Axis in Subjects with Phenylketonuria (PKU): A Review.

The composition and functioning of the gut microbiota, the complex population of microorganisms residing in the intestine, is strongly affected by endogenous and exogenous factors, among which diet is key. Important perturbations of the microbiota have been observed to contribute to disease risk, as in the case of neurological disorders, inflammatory bowel disease, obesity, diabetes, cardiovascular disease, among others. Although mechanisms are not fully clarified, nutrients interacting with the microbiota are thought to affect host metabolism, immune response or disrupt the protective functions of the intestinal barrier. Similarly, key intermediaries, whose presence may be strongly influenced by dietary habits, sustain the communication along the gut-brain-axis, influencing brain functions in the same way as the brain influences gut activity. Due to the role of diet in the modulation of the microbiota, its composition is of high interest in inherited errors of metabolism (IEMs) and may reveal an appealing therapeutic target. In IEMs, for example in phenylketonuria (PKU), since part of the therapeutic intervention is based on chronic or life-long tailored dietetic regimens, important variations of the microbial diversity or relative abundance have been observed. A holistic approach, including a healthy composition of the microbiota, is recommended to modulate host metabolism and affected neurological functions.

Mutation analysis of urea cycle disorders

Urea cycle disorders (UCDs) are a group of autosomal or X-linked, recessively inherited errors of metabolism that lead to severe neurological disease due to insufficient detoxification of excess nitrogen. The resulting hyperammonemia is the key feature of UCDs, but at the same time only a surrogate marker. In the majority of cases, a sole biochemical analysis is indicative but not diagnostic. Therefore, additional means are required and mutation analysis is the method of choice for con- firmation in most cases of UCD. In addition to confirming the diagnosis, mutation analysis enables genetic counseling and prenatal testing and contributes to new research approaches. All genes involved in any of the enzymatic (namely the genes for N-acetylglutamate synthase, NAGS; carbamoylphosphate synthetase, CPS1; ornithine transcarbamylase, OTC; argininosuccinate synthetase, ASS1; argininosuccinate lyase, ASL; arginase, ARG1) or transporter steps (namely the genes for the ornithine/ citrulline antiporter ORNT1, SLC25A15; glutamate/aspartate antiporter citrin, SLC25A13) of the urea cycle are known and thus accessible for genetic testing. In most situations, direct Sanger sequencing using DNA from peripheral blood cells can be done but there are exceptions to this such as in the case of the relatively large CPS1 gene which renders RNA based mutation analysis an attractive alternative. With this review, we provide an overview on the current methods used for mutation analysis of each UCD gene, we mention possible pitfalls and their solutions, and discuss alternative methods which may become standard in the future.

Fifty years of phenylketonuria newborn screening — A great success for many, but what about the rest?

Guthrie's landmark discovery and the subsequent implementation of the first newborn screening programs for phenylketonuria (PKU) and other inherited errors of metabolism (IEM) could be – in a 50year retrospective – easily considered among the greatest advances in medicine. They have not just improved the quality of hundreds of thousands of lives, but also transformed our understanding and approach to PKU and IEM in general. However, according to the available albeit very scarce data, many countries and regions seem not to share the benefits of the last 50years of development. Many of them have not yet introduced the newborn screening for PKU or face significant problems in its implementation. In addition, the issue seems to be underrated by the relevant professional forums. Action to improve the current situation should urgently be taken.

Congenital disorders of glycosylation—a challenging group of IEMs

Congenital disorders of glycosylation (CDG) are a rapidly growing group of inherited errors of metabolism (IEMs) due to an impairment of one or several glycosylation pathways. During recent years over 30 CDG subtypes have been identified at a molecular and biochemical level. The clinical manifestations in CDG are heterogeneous and may be highly variable within the same subtype and even among affected siblings. Novel insights into the extremely complex glycosylation pathways have necessitated several reclassifications of the group of CDG. Today CDG comprise not only the formerly known multisystem glycosylation defects but also some tissue-specific glycosylation defects, implicating a different diagnostic work-up depending on the underlying glycosylation defect. In 2007 the expanding group of CDG is an enormous challenge to all specialists working in the field of IEMs. This review gives a brief overview about the expanded group of CDG and summarizes the main implications for clinicians.