Skip to Content

Simian crease

Definition

A simian crease is a single line that runs across the palm of the hand. People normally have three creases in their palms.

The term "simian crease" is not used much anymore since it tends to have a negative meaning (it refers to monkey or ape). The crease is usually just referred to as a single palmar crease.

Alternative Names

Single palmar crease; Transverse palmar crease; Palmar crease

Considerations

Strong lines (called palmar flexion creases) appear on the palms of the hands and soles of the feet. The palm normally has three of these creases. But sometimes, the horizontal creases join together to form a single one.

Palmar creases develop while the baby is growing in the womb, usually by the 12th week of gestation.

A single palmar crease appears in approximately 1 out of 30 people. Males are twice as likely as females to have this condition. Some palmar creases indicate problems with development and are associated with disorders like Down syndrome.

Causes

A single palmar crease is often a normal finding. However, it may also be associated with:

What to Expect at Your Office Visit

An infant with a single palmar crease may have other symptoms and signs that, when taken together, define a specific syndrome or condition. Diagnosis of that condition is based on a family history, medical history, and complete physical exam.

Your doctor may ask questions such as:

  • Is there a family history of Down syndrome or other disorder associated with a single palmar crease?
  • Does anyone else in the family have a single palmar crease without other symptoms?
  • Did the mother use alcohol while pregnant?
  • What other symptoms do you have?

Based on the answers to these questions, the medical history, and the results of the physical exam, further testing may be necessary.

Review Date: 5/12/2009
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com

Disclaimer: The information contained in this website, and its associated websites, is provided as a benefit to the local community, and the Internet community in general; it does not constitute medical advice. We try to provide quality information, but we make no claims, promises or guarantees about the accuracy, completeness, or adequacy of the information contained in or linked to this website and its associated sites. As medical advice must be tailored to the specific circumstances of each patient and healthcare is constantly changing, nothing provided herein should be used as a substitute for the advice of a competent physician. Furthermore, in providing this service, Adventist HealthCare does not condone or support all of the content covered in this site. As an Adventist health care organization, Adventist HealthCare acts in accordance with the ethical and religious directives for Adventist health care services.

Adventist HealthCare · 301-315-3030 · 1801 Research BLVD, Suite 400, Rockville, MD 20850

Submit an Online Information Request