Laron Syndrome

National Organization for Rare Disorders, Inc.

It is possible that the main title of the report Laron Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • GHBP
  • GHR
  • Growth Hormone Binding Protein Deficiency or Dysfunction
  • Growth Hormone Receptor Deficiency or Dysfunction
  • Laron Type Pituitary Dwarfism I
  • LTD1
  • Pituitary Dwarfism II
  • Laron Dwarfism

Disorder Subdivisions

  • None

General Discussion

Laron syndrome type I (LTD1) a rare genetic disorder, is caused by the body's inability to use the growth hormone (GH) that it produces. The problem lies not in the production of growth hormone but rather in a defective GH-receptor gene. This defect prevents the proper binding of the GH molecule, leaving high levels of unbound growth hormone in the plasma.

Laron syndrome is characterized by short stature and delayed bone age, as well as high levels of circulating growth hormone.

A second form of the disorder known as Laron syndrome type II (LTD2) shows typical clinical features of the Laron syndrome but is due to a defect in the biochemical processing of growth hormone after the hormone has been bound on the cell surface.


Human Growth Foundation
997 Glen Cove Avenue
Glen Head, NY 11545
Tel: (516)671-4041
Fax: (516)671-4055
Tel: (800)451-6434

MAGIC Foundation
6645 W. North Avenue
Oak Park, IL 60302
Tel: (708)383-0808
Fax: (708)383-0899
Tel: (800)362-4423

Little People's Research Fund, Inc.
616 Old Edmondson Avenue
2nd Floor
Catonsville, MD 21228-3305
Tel: (410)747-1100
Fax: (410)747-1374
Tel: (800)232-5773

Little People of America, Inc.
250 El Camino Real
Suite 201
Tustin, CA 92780
Tel: (714)368-3689
Fax: (714)368-3367
Tel: (888)572-2001

MUMS National Parent-to-Parent Network
150 Custer Court
Green Bay, WI 54301-1243
Tel: (920)336-5333
Fax: (920)339-0995
Tel: (877)336-5333

Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
TDD: (888)205-3223

For a Complete Report

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc. ® (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see

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