Palmar crease

Palmar creases, also known as simian lines, are the lines in the palm of the human hand. They are formed during fetal development and are unique to each individual. The three major palmar creases are the radial longitudinal crease, the proximal transverse crease, and the distal transverse crease.

Formation[edit | edit source]

Palmar creases are formed in the womb around the 12th week of gestation. They are influenced by both genetic and environmental factors. The creases are formed where the skin on the palm folds or bends. They are permanent and do not change throughout a person's life.

Types of Palmar Creases[edit | edit source]

There are three major types of palmar creases: the radial longitudinal crease, the proximal transverse crease, and the distal transverse crease. The radial longitudinal crease runs from the base of the thumb towards the wrist. The proximal transverse crease runs across the palm, roughly parallel to the base of the fingers. The distal transverse crease runs across the palm, closer to the fingers than the proximal transverse crease.

Clinical Significance[edit | edit source]

In some cases, the presence of a single palmar crease (known as a simian crease) can be a sign of a genetic disorder such as Down syndrome or Fetal alcohol syndrome. However, a single palmar crease can also be found in people without any genetic disorders. It is important to note that the presence of a single palmar crease is not a definitive diagnosis of any condition, but rather a possible indicator that further testing may be needed.