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Genetic and Rare Diseases Information Center (GARD)

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Down syndrome


* Not a rare disease
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Other Names for this Disease
  • Down's syndrome
  • Trisomy 21
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Your Question

I have a single palmar crease on both of my hands.  Do I have an increased chance of having a child with Down syndrome or another chromosome disorder?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is a single tranverse palmar crease?

A single transverse palmar crease (previously called a "simian crease") is when there is a single line across the palm of the hand. This is a variation of the usual three palm creases that are seen. Palm creases develop before birth, by the first trimester of pregnancy. Whether or not someone has a single palmar crease is influenced by many factors including race, sex, and heredity. The single transverse palmar crease is a normal variation seen in about 1 in 30 people.[1]
Last updated: 6/8/2011

Is a single transverse palmar crease associated with chromosome disorders?

A single transverse palmar crease is usually a normal variation in the appearance of the hand. It is also seen in individuals with prenatal exposures such as fetal alcohol syndrome, genetic conditions such as Aarskog syndrome, and chromosome disorders such as Down syndrome or trisomy 13.[1][2]
Last updated: 6/8/2011

Does having a single transverse palmar crease increase a person's chance of having a child with a chromosome disorder?

No, a single transverse palmar crease is not associated with an increased risk to have a child with a chromosome disorder. Most cases of Down syndrome and other chromosome disorders are not inherited from either parent, but occur due to a random event during the formation of reproductive cells.[3]
Last updated: 6/8/2011