Epicanthal folds are nothing but skin folds of upper eyelid covering the inner corner of the eye, they are also known as plica palpebronasalis. Elevation of nasal bridge is associated with the epicanthal folds.
- Epicanthal fold is normal for Asiatic and some non-Asian people. These can also be present in young children.
- Down syndrome
- Fetal alcohol syndrome.
- Turner syndrome.
- Williams’s syndrome.
- Noonan syndrome.
- Geographic distribution- Epicanthic folds appear in east Asians, southeast Asian, central Asians, and some South Asians, indigenous Americans, the Khoisan, Madagascar, and occasionally in Europeans and among nilotes.
- Age – Many fetuses lose their epicanthic folds after three to six months of gestation.
- Medical condition – Sometimes it can be inherited from the parents, it is a medical condition in which nasal bridge is not mature and projects because of which epicanthic folds are formed. In case of Down syndrome, about 60% patients have epicanthic folds.
Epicanthic folds can be found in infants and in children’s of any race and it is a normal foundation, the formation of these folds is related to tension in underlying muscles. There are many surgical techniques by which we can correct them. A technique is used for these folds to involve an incision on the fold and then remove the muscle below the fold and then attaching the skin edge to the deep tissue.
Epicanthic folds occur more frequently In Asiatic groups and those people genetically linked to Asia. It is not present universally in these people and it occurs rarely in other groups. The epicanthic folds vary among the nine geographic races. To define the presence of these folds as by looking externally is more difficult as compared to genotype but at that time it was problematic and unreliable.
There is variation among phenotype in geographical races by environmental conditions or by some other reasons like individual variation, the presence and absence of epicanthic folds may be used as diagnosing tool for many genetic diseases.
The association of epicanthic folds with Mongolians and Asians more generally served to reinforce racial and cultural supremacy in 19th and mid 20th century. Humans with the genetic disorder Down syndrome caused by having three copies of chromosome no 21 have limited physical growth, and mental retardation and risk of other serious problems. The Down syndrome infants quickly recognized by facial and more general characteristics including the rounded head, short neck, thin and fine hair and especially by epicanthic folds.
In addition to Down syndrome, the epicanthic folds can be seen in other genetic disorders like trigonocephaly, ptosis, and epicanthus inversus syndrome. In latter case the epicanthic fold is inverted, extending from the lower eyelid up to the nose. Folds also occur in certain congenital conditions like fetal alcohol syndrome etc.