Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
  • Clinical Research and Public Health
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Video Abstracts
  • Reviews
    • View all reviews ...
    • Complement Biology and Therapeutics (May 2025)
    • Evolving insights into MASLD and MASH pathogenesis and treatment (Apr 2025)
    • Microbiome in Health and Disease (Feb 2025)
    • Substance Use Disorders (Oct 2024)
    • Clonal Hematopoiesis (Oct 2024)
    • Sex Differences in Medicine (Sep 2024)
    • Vascular Malformations (Apr 2024)
    • View all review series ...
  • Viewpoint
  • Collections
    • In-Press Preview
    • Clinical Research and Public Health
    • Research Letters
    • Letters to the Editor
    • Editorials
    • Commentaries
    • Editor's notes
    • Reviews
    • Viewpoints
    • 100th anniversary
    • Top read articles

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Video Abstracts
  • In-Press Preview
  • Clinical Research and Public Health
  • Research Letters
  • Letters to the Editor
  • Editorials
  • Commentaries
  • Editor's notes
  • Reviews
  • Viewpoints
  • 100th anniversary
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
Top
  • View PDF
  • Download citation information
  • Send a comment
  • Terms of use
  • Standard abbreviations
  • Need help? Email the journal
  • Top
  • Abstract
  • Version history
Article has an altmetric score of 3

See more details

Referenced in 2 patents
18 readers on Mendeley
  • Article usage
  • Citations to this article (40)

Advertisement

Research Article Free access | 10.1172/JCI106688

Biochemical and genetic studies in cystinuria: observations on double heterozygotes of genotype I/II

Claude L. Morin, Margaret W. Thompson, Sanford H. Jackson, and Andrew Sass-Kortsak

Department of Paediatrics, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Medical Cell Biology, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Pathological Chemistry, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Find articles by Morin, C. in: JCI | PubMed | Google Scholar

Department of Paediatrics, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Medical Cell Biology, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Pathological Chemistry, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Find articles by Thompson, M. in: JCI | PubMed | Google Scholar

Department of Paediatrics, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Medical Cell Biology, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Pathological Chemistry, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Find articles by Jackson, S. in: JCI | PubMed | Google Scholar

Department of Paediatrics, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Medical Cell Biology, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Department of Pathological Chemistry, Faculty of Medicine, University of Toronto, and The Research Institute, The Hospital for Sick Children, Toronto, 2. Canada

Find articles by Sass-Kortsak, A. in: JCI | PubMed | Google Scholar

Published September 1, 1971 - More info

Published in Volume 50, Issue 9 on September 1, 1971
J Clin Invest. 1971;50(9):1961–1976. https://doi.org/10.1172/JCI106688.
© 1971 The American Society for Clinical Investigation
Published September 1, 1971 - Version history
View PDF
Abstract

10 families with cystinuria were investigated by measuring: (a) quantitative 24 hr urinary excretion of amino acids by column chromatography; (b) endogenous renal clearances of amino acids and creatinine; (c) intestinal uptake of 34C-labeled L-cystine, L-lysine, and L-arginine using jejunal mucosal biopsies; (d) oral cystine loading tests. All four of these were studied in the probands and the first two in a large number of the family members.

49 members of 8 families were found to have a regular genetic pattern as described previously by Harris, Rosenberg, and their coworkers.

Clinical or biochemical differences between the homozygotes type I (recessive cystinuria) and homozygotes type II (incompletely recessive cystinuria) have not been found. Both types excreted similarly excessive amounts of cystine, lysine, arginine, and ornithine, and had high endogenous renal clearances for these four amino acids. Some homozygotes of both types had a cystine clearance higher than the glomerular filtration rate. Jejunal mucosa from both types of homozygotes exhibited near complete inability to concentrate cystine and lysine in vitro. This was also documented in vivo with oral cystine loads.

The heterozygotes type I were phenotypically normal with respect to the above four measurements. The heterozygotes type II showed moderate but definite abnormalities in their urinary excretion and their renal clearances of dibasic amino acids. Of the four amino acids concerned, cystine was the most reliable marker to differentiate between the heterozygotes type II and the homozygous normals.

In this study, type III cystinuria, as described by Rosenberg, was not encountered.

In two additional families, double heterozygotes of genotype I/II were found. The disease affecting these is clinically and biochemically less severe than that affecting homozygotes of either type I or type II. With respect to the four parameters used in this study, the double heterozygotes type I/II have results which are intermediate between those of the homozygotes type I and II and those of the heterozygotes type II.

Images.

Browse pages

Click on an image below to see the page. View PDF of the complete article

icon of scanned page 1961
page 1961
icon of scanned page 1962
page 1962
icon of scanned page 1963
page 1963
icon of scanned page 1964
page 1964
icon of scanned page 1965
page 1965
icon of scanned page 1966
page 1966
icon of scanned page 1967
page 1967
icon of scanned page 1968
page 1968
icon of scanned page 1969
page 1969
icon of scanned page 1970
page 1970
icon of scanned page 1971
page 1971
icon of scanned page 1972
page 1972
icon of scanned page 1973
page 1973
icon of scanned page 1974
page 1974
icon of scanned page 1975
page 1975
icon of scanned page 1976
page 1976
Version history
  • Version 1 (September 1, 1971): No description

Article tools

  • View PDF
  • Download citation information
  • Send a comment
  • Terms of use
  • Standard abbreviations
  • Need help? Email the journal

Metrics

Article has an altmetric score of 3
  • Article usage
  • Citations to this article (40)

Go to

  • Top
  • Abstract
  • Version history
Advertisement
Advertisement

Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts

Referenced in 2 patents
18 readers on Mendeley
See more details