Simian crease

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Simian crease

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

Single palmar crease

Prominent creases (called flexion creases) appear on the palms of the hands and soles of the feet. The palm normally has three flexion creases. Sometimes, the two horizontal creases fuse to form a single crease. This is called a single palmar crease, or simian crease.

Many structures develop in the fetus in the first few months of gestation. Palmar creases develop early, by the 12th week of life. Some abnormalities in palmar creases indicate problems with development and are associated with disorders like Down syndrome. However, a simian crease appears in approximately 1 out of 30 people. Males are twice as likely as females to have this condition.

A simian crease is often a normal finding, occurring in about 3% of the population. It may also be associated with:

• Down syndrome
• Aarskog syndrome
• Cohen syndrome
• Fetal alcohol syndrome
• Trisomy 13
• Rubella syndrome
• Turner syndrome
• Klinefelter syndrome
• Pseudohypoparathyroidism
• Gonadal dysgenesis
• Cri du chat syndrome

Review Date: 05/10/2006
Reviewed By: Daniel Rauch, MD, FAAP, Director, Pediatric Hospitalist Program, Associate Professor of Pediatrics, NYU School of Medicine, New York, NY. Review provided by VeriMed Healthcare Network.