19 March 2010: Amino Acids Seminar

Fri, 2024-03-19


Inborn errors of amino acid metabolism 
Fumio Endo, MD, PhD
Department of Pediatrics, Kumamoto University, School of Medicine
There are numbers of disorders belong to inborn errors of metabolism, including phenylketonuria. Among these inborn errors, today, I will focused on inborn errors of urea cycle disorders.
Various disorders cause hyperammonemia during childhood. Amongthem are those caused by inherited defects in urea synthesisand related metabolic pathways. These disorders can be groupedinto two types: disorders of the enzymes that comprise the ureacycle, and disorders of the transporters or metabolites of theamino acids related to the urea cycle.
Principal clinical featuresof these disorders are caused by elevated levels of blood ammonium.Additional disease-specific symptoms are related to the particularmetabolic defect. These specific clinical manifestations areoften due to an excess or lack of specific amino acids. Treatmentof urea cycle disorders and related metabolic diseases consistsof nutritional restriction of proteins, administration of specificamino acids, and use of alternative pathways for discardingexcess nitrogen.


Although combinations of these treatments areextensively employed, the prognosis of severe cases remainsunsatisfactory. Liver transplantation is one alternative forwhich a better prognosis is reported. In Japan, urea cycle disorders (UCDs) are one of the most frequent inborn errors of metabolism, estimated to have a prevalence of 1 per 50,000 live births.
EU regulatory issues related to amino acid use in food
Miro Smriga, PhD
Ajinomoto Co., Inc., Tokyo (former ICAAS Europe)
European Union (EU) exercises a significant regulatory influence in the field of food law, especially vis-à-vis developing nations. Following the European regulatory situation has therefore a fundamental importance for globally active producers and users of amino acids. While the “single market” concept has been one of the foundations of the EU, the amino acid use in foods and supplements still remains fragmented and regulatory situation differs among the member states.
The use of amino acids in foods in EU is determined by two major regulations, Reg. 1925/2006 which governs fortification of foods with nutrients, and Reg. 1924/2006 which defines the positive list of nutritional and health claims on foods. ICAAS Europe has applied for 5 health claims (BCAA, Gln, Arg, Lys and Met) out of which three were refused due to insufficient efficacy data in humans, and two are still awaiting a scientific evaluation by the European Food Safety Authority. The existence of a legal framework to determine the use of health claims on foods (Reg. 1924/2006) challenges a twenty-year-old system (Dir. 89/398) of “foods for particular nutritional use”, especially in the area of sport applications and weight reduction. Changes in that area of the European food law are expected in near future.
One of the aims of ICAAS Europe has been to address the issues of rapidly evolving regulatory environment that is representing certain strategic challenge to the future use of amino acids in Europe and world-wide.Moreover, the ICAAS Europe provided a platform for an active collaboration of the member companies for the challenges represented by the REACH regulation (Reg. 1907/2006) which stipulates the Registration, Evaluation, Authorization and Restriction of Chemical substances sold or used within the EU.
The lessons of the ICAAS Europe initial activity in the period between 2007 and 2009 could be summarized as follows: (A) there is a need for local dedicated staff knowledgeable in both amino acid science and regulatory situation, (B) to endorse amino acids as safe and useful substances; significant attention should be paid to regulatory and QA work, and to promoting amino acids towards regulatory opinion makers.