Sophia M Khan, Robyn R Heister, Justine R Keathley
{"title":"基因携带者不受影响吗?苯丙酮尿症(PKU)遗传携带者的代谢和健康结果文献综述。","authors":"Sophia M Khan, Robyn R Heister, Justine R Keathley","doi":"10.1159/000540549","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Phenylketonuria (PKU) is an autosomal recessive genetic condition that results in reduced enzymatic functioning within the phenylalanine hydroxylase (PAH) pathway, which is involved in the metabolism of phenylalanine (Phe) into tyrosine (Tyr). Without dietary intervention, individuals with PKU exhibit significantly elevated levels of Phe, which is presumed to cause severe neurological dysfunction and other associated health risks. Carriers of PKU are heterozygotes for a PAH gene mutation and are typically described in the literature as \"unaffected.\" However, decades of existing research challenges this classical thinking and it is plausible that these individuals currently classified as carriers may present with an intermediate phenotype or may be \"moderately affected.\"</p><p><strong>Summary: </strong>The purpose of this scoping review was to explore this hypothesis further, by searching for and summarizing existing literature on metabolism and health outcomes among PKU carriers. Preliminary research has suggested that some PKU carriers exhibit reduced PAH enzyme function, and relatedly, elevated circulating Phe levels compared to noncarriers. In addition, Phe dosing trials have further demonstrated that carriers have increased Phe levels and decreased Tyr levels compared to noncarriers. Because of these metabolic perturbations, it is biologically plausible for carriers to experience an intermediate phenotype in terms of metabolic consequences and clinical outcomes. While these outcomes have yet to be thoroughly explored, early research has found associations between PKU carrier status and lower IQs as well as decreased executive functioning, memory, processing speed, and inhibitory control. The PAH pathway is also involved in melanogenesis, and research has demonstrated increased melanoma risk among PKU carriers. However, there are many limitations to this research, and thus whether or not carriers are clinically impacted cannot yet be conclusively determined.</p><p><strong>Key message: </strong>Overall, while preliminary research suggests a possible intermediate phenotype among PKU carriers, the current available research is limited and PKU carriers are still clinically considered \"unaffected.\" This review outlines the current literature while discussing future research endeavors related to the metabolism and health of PKU carriers.</p>","PeriodicalId":18030,"journal":{"name":"Lifestyle Genomics","volume":" ","pages":"102-112"},"PeriodicalIF":2.0000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Are Carriers Unaffected? A Literature Review of Metabolic and Health Outcomes among Genetic Carriers of Phenylketonuria.\",\"authors\":\"Sophia M Khan, Robyn R Heister, Justine R Keathley\",\"doi\":\"10.1159/000540549\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Phenylketonuria (PKU) is an autosomal recessive genetic condition that results in reduced enzymatic functioning within the phenylalanine hydroxylase (PAH) pathway, which is involved in the metabolism of phenylalanine (Phe) into tyrosine (Tyr). Without dietary intervention, individuals with PKU exhibit significantly elevated levels of Phe, which is presumed to cause severe neurological dysfunction and other associated health risks. Carriers of PKU are heterozygotes for a PAH gene mutation and are typically described in the literature as \\\"unaffected.\\\" However, decades of existing research challenges this classical thinking and it is plausible that these individuals currently classified as carriers may present with an intermediate phenotype or may be \\\"moderately affected.\\\"</p><p><strong>Summary: </strong>The purpose of this scoping review was to explore this hypothesis further, by searching for and summarizing existing literature on metabolism and health outcomes among PKU carriers. Preliminary research has suggested that some PKU carriers exhibit reduced PAH enzyme function, and relatedly, elevated circulating Phe levels compared to noncarriers. In addition, Phe dosing trials have further demonstrated that carriers have increased Phe levels and decreased Tyr levels compared to noncarriers. Because of these metabolic perturbations, it is biologically plausible for carriers to experience an intermediate phenotype in terms of metabolic consequences and clinical outcomes. While these outcomes have yet to be thoroughly explored, early research has found associations between PKU carrier status and lower IQs as well as decreased executive functioning, memory, processing speed, and inhibitory control. The PAH pathway is also involved in melanogenesis, and research has demonstrated increased melanoma risk among PKU carriers. However, there are many limitations to this research, and thus whether or not carriers are clinically impacted cannot yet be conclusively determined.</p><p><strong>Key message: </strong>Overall, while preliminary research suggests a possible intermediate phenotype among PKU carriers, the current available research is limited and PKU carriers are still clinically considered \\\"unaffected.\\\" This review outlines the current literature while discussing future research endeavors related to the metabolism and health of PKU carriers.</p>\",\"PeriodicalId\":18030,\"journal\":{\"name\":\"Lifestyle Genomics\",\"volume\":\" \",\"pages\":\"102-112\"},\"PeriodicalIF\":2.0000,\"publicationDate\":\"2024-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Lifestyle Genomics\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1159/000540549\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/7/30 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"GENETICS & HEREDITY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Lifestyle Genomics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1159/000540549","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/7/30 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
Are Carriers Unaffected? A Literature Review of Metabolic and Health Outcomes among Genetic Carriers of Phenylketonuria.
Background: Phenylketonuria (PKU) is an autosomal recessive genetic condition that results in reduced enzymatic functioning within the phenylalanine hydroxylase (PAH) pathway, which is involved in the metabolism of phenylalanine (Phe) into tyrosine (Tyr). Without dietary intervention, individuals with PKU exhibit significantly elevated levels of Phe, which is presumed to cause severe neurological dysfunction and other associated health risks. Carriers of PKU are heterozygotes for a PAH gene mutation and are typically described in the literature as "unaffected." However, decades of existing research challenges this classical thinking and it is plausible that these individuals currently classified as carriers may present with an intermediate phenotype or may be "moderately affected."
Summary: The purpose of this scoping review was to explore this hypothesis further, by searching for and summarizing existing literature on metabolism and health outcomes among PKU carriers. Preliminary research has suggested that some PKU carriers exhibit reduced PAH enzyme function, and relatedly, elevated circulating Phe levels compared to noncarriers. In addition, Phe dosing trials have further demonstrated that carriers have increased Phe levels and decreased Tyr levels compared to noncarriers. Because of these metabolic perturbations, it is biologically plausible for carriers to experience an intermediate phenotype in terms of metabolic consequences and clinical outcomes. While these outcomes have yet to be thoroughly explored, early research has found associations between PKU carrier status and lower IQs as well as decreased executive functioning, memory, processing speed, and inhibitory control. The PAH pathway is also involved in melanogenesis, and research has demonstrated increased melanoma risk among PKU carriers. However, there are many limitations to this research, and thus whether or not carriers are clinically impacted cannot yet be conclusively determined.
Key message: Overall, while preliminary research suggests a possible intermediate phenotype among PKU carriers, the current available research is limited and PKU carriers are still clinically considered "unaffected." This review outlines the current literature while discussing future research endeavors related to the metabolism and health of PKU carriers.
期刊介绍:
Lifestyle Genomics aims to provide a forum for highlighting new advances in the broad area of lifestyle-gene interactions and their influence on health and disease. The journal welcomes novel contributions that investigate how genetics may influence a person’s response to lifestyle factors, such as diet and nutrition, natural health products, physical activity, and sleep, amongst others. Additionally, contributions examining how lifestyle factors influence the expression/abundance of genes, proteins and metabolites in cell and animal models as well as in humans are also of interest. The journal will publish high-quality original research papers, brief research communications, reviews outlining timely advances in the field, and brief research methods pertaining to lifestyle genomics. It will also include a unique section under the heading “Market Place” presenting articles of companies active in the area of lifestyle genomics. Research articles will undergo rigorous scientific as well as statistical/bioinformatic review to ensure excellence.