Epicanthal Folds

Epicanthal folds refer to the folded skin of the upper eyelids which covers the upper inner corner, known as the canthus of the eye. It stretches from the nasal corner of the eye to the inferior side of the eyebrow. Eyes with this folds look almond shaped or boat shaped. Along with East Asian people, these are common in children with inherited genetic diseases. It may occur to fetuses or newborn children of any race before the nose bridge starts elevating. The folds can be fully developed or less developed and may change shape or decrease in size with age.

Causes of Epicanthal Creases

The cause of epicanthus in East Asian people is still in doubt and there are various theories that hold genes, complex anatomy and the environment responsible for this. For other races, the causes of epicanthus folds can be associated with various genetic disorders.

Down Syndrome
It is a congenital disorder that affects the body as well the mind and causes mental retardation. It occurs due to an error in the mother's egg, that causes the extra 21st chromosome to attach to the normal pair. It can be diagnosed in the womb by performing tests during pregnancy. After birth it is identified by the physical appearance of the child. Children affected with Down Syndrome have a flat face and short stature. The flat face includes epicanthal creases, which make them appear like Mongolian people.

Turner Syndrome
Turner Syndrome is a rare genetic disorder which occurs when a single X chromosome is left unpaired. Such patients are women with 45 chromosomes. Fetuses detected with Turner Syndrome are generally aborted, but those who survive can be identified by certain physical characteristics, such as webbed neck, shield chest, short stature, cubitus valgus, lymphedema, and skeletal, autoimmune, dermatological, and renal complications. Such skin and bone complications in the body cause these folds.

Fatal Alcohol Syndrome
As the name suggests, this is caused by excessive alcohol consumed by the mother during pregnancy. The alcohol can arm the fetus resulting in low birth weight, delayed growth, thin upper lip, short palpebral fissures and unusual facial features. This may result in the folds in canthus of the eye.

William Syndrome
Children with William Syndrome are prone to heart diseases, hypertension, and kidney problems. Such children have different physical characteristics, such as elfin facial features including epicanthus, small stature for age, and gregarious personalities.

Noonan Syndrome
This is a rare congenital disorder that results in chest deformity, undescended testes and pulmonic stenosis. Children affected with Noonan Syndrome possess short stature, drooping upper eyelid along with epicanthal creases, and widely spaced eyes. Such children are also mentally challenged.

Wolf-Hirschhorn Syndrome
This is a rare inherited chromosomal disorder that affects the mental and physical growth of the child. It is more common in female babies than male babies. Such kids are attributed with wide set of eyes, prominent forehead, broad and beaked nose, small head, seizures, mental retardation, malformation of hands, chest, feet, spine, heart, and underdeveloped genitals and urinary organs.

Given above is not an exhaustive list of genetic disorders, as there are lot of other rare genetic diseases and disorders such as Rubinstein-Tayabi Syndrome, Blepharophimosis Syndrome, and Trisomy 18, that have harmful effects on children and cause epicanthal creases.

Apart from congenital disorders, there is no other apparent cause found for folds in people from other races than East Asian. In East Asian people, epicanthal folds neither pose any danger nor is the result of any disorder. According to the evolution theory, it may be a necessary variation in human genetics and adaptive feature that helps people adjust with natural local conditions. For example, these folds are common in people living in snowy regions, desserts, etc. Such eye design helps them protect themselves from strong winds, cold weather, and harsh UV rays. However, why the epicanthal fold trait exists is still unknown by medical science.