The absence of a convenient, direct enzymatic assay for detecting phenylketonuria (PKU) heterozygotes together with the difficulty of the molecular testing due to the large number of mutations in the phenylalanine hydroxylase ( PAH ) gene has resulted in continued effort to develop an accurate procedure to discriminate the heterozygous individuals from the homozygous normal population. Aiming to find out a method that is simple and reliable for PKU carrier screening, we compared the biochemical data of 20 known PKU obligate heterozygotes with those of 45 presumed normal homozygous controls. Fasting blood samples from all subjects were analyzed for plasma phenylalanine and tyrosine using an amino-acid analyzer. Micromolar plasma concentrations of phenylalanine and tyrosine in addition to Phe/Tyr and Phe 2 /Tyr ratios were determined and statistical analysis of the difference between the two groups was done using the student’s t test. Mean values for phenylalanine concentrations, Phe/Tyr and Phe 2 /Tyr ratios were significantly higher in PKU heterozygotes than in control subjects. In addition, ROC curve analysis was performed for the same four biochemical variables. The value for the area under the curve (ROC AUC ) was obtained for each parameter with the Phe 2 /Tyr ratio having an area of 1, which means that it had perfect discrimination. When the ratio Phe/Tyr was plotted against the Phe 2/Tyr, all the studied control subjects and none of the PKU carriers fell below the values 1.2 and 80,

Detection of Heterozygous Carriers of PKU in Egypt: Successful Application of a Simple Biochemical Method.

Phenylketonuria (PKU) is an inherited metabolic disorder derived from a deficiency in the enzyme phenylalanine hydroxylase, which converts the amino acid phenylalanine (Phe) into tyrosine (Tyr). Here we aimed to examine the metabolism of Phe and Tyr in heterozygotes for PKU during fasting and after oral overload of Phe (25 mg/kg). Plasma concentration of Phe and Tyr and Phe2–Tyr ratio were determined under fasting condition or 30, 45, 60, and 90 minutes after Phe overload. The sample consisted of 50 participants: 23 heterozygotes for PKU (10 men and 13 women) and a control group of 27 healthy individuals (13 men and 14 women). The dosage of Phe at 45 and 90 minutes and the micromolar fraction of Phe2/Tyr after 90 minutes of overload efficiently differentiated PKU heterozygotes. The discriminant function revealed 86% of accuracy. In fact, 94.4% of heterozygotes for PKU were correctly classified.

/pdf/phenylalanine-and-tyrosine-metabolism-analysis-in-2b9l5wswgc.pdf

Phenylalanine and Tyrosine Metabolism Analysis in Heterozygotes for Phenylketonuria and in Healthy Individuals

OBJECTIVE To find out a method that is simple and reliable for screening phenylketonuria(PKU) heterozygotes. METHODS Detecting and analyzing plasma phenylalanine(Phe) and tyrosine(Tyr) from 101 known-PKU heterozygotes and 2023 married people by means of a high performance liquid chromatograph. RESULTS Significant differences were observed between known- PKU heterozygotes and screening population in plasma Phe, Phe/Tyr and Phe(2)/Tyr. The values of plasma Phe, Phe/Tyr and Phe(2)/ Tyr from 94.1% known-PKU heterozygotes were higher than mean+2s of those values from screening population. According to the limits of mean+2s, 81 cases were screened out from the 2023 married people. It was the first time to get the actual heterozygote frequency of 4% from population. CONCLUSION The biochemical method mentioned above is available for use in screening PKU heterozygotes.

A study of phenylketonuria heterozygotes screening in married population of Tianjin area

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Ding Z

Author Tools

Chat about Author

Papers

A study of phenylketonuria heterozygotes screening in married population of Tianjin area