Epicanthal fold, also known as ‘epicanthus’, is a common feature found in people with East Asian descent. However, for others it is the result of some congenital disorders. The following article sheds some light on this feature.
Epicanthal fold refers to the folded skin of the upper eyelids that covers the upper inner corner (called canthus) of the eye. It stretches from the nasal corner to the interior side of the eyebrow. Eyes with this fold look almond-shaped or boat-shaped. Along with East Asian people, such eyes are common in children with inherited genetic diseases. Epicanthus may occur to fetuses or newborn children of any race, before the nose bridge starts elevating. The folds can be fully or less developed, and may change shape or decrease in size with age.
The cause of epicanthus in East Asian people is still not known; however, there are various theories that hold the genes, complex anatomy, and the environment, responsible for developing this feature. For other races, the causes can be associated with various genetic disorders such as:
It is a congenital disorder that affects the body, as well as 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 fetus, by performing tests during pregnancy. After birth, it is identified by the physical appearance of the child. Children affected by Down Syndrome have a flat face and short stature. The face is characterized by epicanthal creases, which make them appear like Mongolian people.
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 related complications lead to the development of these folds.
Fetal Alcohol Syndrome
This disorder is caused due to excessive consumption of alcohol by the mother-to-be during pregnancy. The alcohol can be harmful to the fetus by increasing the risk of low birth weight, delayed growth, thin upper lip, short palpebral fissures, and unusual facial features. This may lead to folds in the canthus of the eye.
Children with Williams Syndrome are prone to heart diseases, hypertension, and kidney problems. They exhibit “elfin” facial features along with epicanthus.
This is a rare congenital disorder that results in chest deformity, undescended testes, and pulmonic stenosis. Children affected by this disorder possess short stature, drooping upper eyelid along with epicanthal creases, and widely spaced eyes.
This is a rare inherited chromosomal disorder that affects the mental and physical growth of the child. It is more common in female infants than male infants. 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.
Apart from the aforementioned list of genetic disorders, there are other rare genetic disorders such as Rubinstein-Taybi Syndrome, Blepharophimosis Syndrome, and Trisomy 18, that have harmful effects on children and cause epicanthal creases. In East Asian people, epicanthal folds neither pose any danger nor are 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, deserts, etc. Such eye design helps them protect themselves from strong winds, cold weather, and harsh UV rays.
Disclaimer: This HealthHearty article is for informative purposes only, and should not be used as a replacement for expert medical advice.