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 usage
  • Citations to this article

Advertisement

Research Article Free access | 10.1172/JCI115609

Molecular basis of lactase levels in adult humans.

J C Escher, N D de Koning, C G van Engen, S Arora, H A Büller, R K Montgomery, and R J Grand

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by Escher, J. in: PubMed | Google Scholar

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by de Koning, N. in: PubMed | Google Scholar

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by van Engen, C. in: PubMed | Google Scholar

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

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

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by Büller, H. in: PubMed | Google Scholar

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by Montgomery, R. in: PubMed | Google Scholar

Department of Pediatrics, Boston Floating Hospital, Massachusetts.

Find articles by Grand, R. in: PubMed | Google Scholar

Published February 1, 1992 - More info

Published in Volume 89, Issue 2 on February 1, 1992
J Clin Invest. 1992;89(2):480–483. https://doi.org/10.1172/JCI115609.
© 1992 The American Society for Clinical Investigation
Published February 1, 1992 - Version history
View PDF
Abstract

The molecular basis of adult human "lactase deficiency" has long been a subject of controversy. To address this issue, small intestinal biopsies from orienta, black, and white patients were analyzed. Adjacent samples were assayed for lactase and sucrase specific activities and the sucrase/lactase ratio (high ratio signifies lactase deficiency), and the results were compared to lactase steady-state mRNA levels detected in Northern blots probed with a human lactase mDNA. All oriental patients had high ratios and no detectable lactase mRNA. Four black patients had a similar pattern; two with low ratios had detectable mRNA. The group of white patients displayed a range of findings, from high ratio/no mRNA to low ratio/considerable mRNA. Elevated levels of lactase mRNA always correlated with the presence of elevated levels of lactase enzyme activity, suggesting that the difference in levels of adult human intestinal lactase activity among racial groups may be regulated at the level of gene transcription.

Images.

Browse pages

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

icon of scanned page 480
page 480
icon of scanned page 481
page 481
icon of scanned page 482
page 482
icon of scanned page 483
page 483
Version history
  • Version 1 (February 1, 1992): No description

Article tools

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

Metrics

  • Article usage
  • Citations to this article

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