Simian crease

Alternative names:

single palmar crease

Definition:

A simian crease is a single palmar crease (across the palm) as compared to the two normal creases.

Considerations:

Prominent creases, called flexion creases, normally appear on the palms of the hands and soles of the feet as part of the hand print and foot print. The palm normally has three flexion creases. Sometimes, the two horizontal creases fuse to form a single crease, called a single palmar crease or a simian crease.

Many structures develop in the first few months of gestation. Palmar creases develop early, by the 11th to 12th week of gestation. Abnormalities in palmar creases may indicate problems with the early development of the fetus and other associated abnormalities. A single palmar crease or simian crease appears in approximately 1 out of 30 normal people. Of normal people with simian creases, males are twice as likely as females to exhibit this trait.

Common causes:

• normal finding (approximately 3% of the population)
• Down's syndrome
• Aarskog syndrome
• Cohen syndrome
• fetal alcohol syndrome
• trisomy 13
• rubella syndrome
• Turner's syndrome
• Klinefelter's syndrome
• pseudohypoparathyroidism
• gonadal dysgenesis
• cri du chat syndrome

Note: There may be other causes of a simian crease. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Use the Symptom Analysis option to explore the possible explanations for a simian crease, occurring alone or in combination with other problems.

Update Date: 02/09/00
Updated by: J. Gordon Lambert, MD, Associate Medical Director, Utah Health Informatics and adam.com editorial