It is important only because prominent epicanthic folds may give a false impression of crossed eyes in children. .
The eyes may have white or light-yellow speckling around the rum of the iris. These specks are called Brushfield spots, and may be present in the eyes of normal children. They often disappear later if the iris turns brown. Like epicanthic folds, they do not interfere with vision.
Mouth. The mouth cavity is slightly smaller than average, and the tongue slightly larger. This combination encourages some children to acquire the habit of putting out their tongues at times.
Hands. The hands tend to be broad, with short fingers. The little finger sometimes has only one joint instead of the usual two. This finger may also be slightly curbed towards the other fingers. The palm may have only one cease going across it or, if there are two, both may extend right across the hand.
Body size. Children with Down syndrome usually weigh less than average at birth. Their length at birth is similarly reduces. During childhood, they grow steadily but slowly, and their ultimate height as adults is generally shorter than would be expected for their family. It is usually near the bottom of the normal range, and is approximately 145 to 168 cm in men and 132 to 155 cm in women.
One of the more notable aspects of Down syndrome is the wide variety of features and characteristics of people with trisomy 21: There is a wide range of mental retardation and developmental delay noted among children with Down syndrome. Some babies are born with heart defects and others are not. Some children have associated illnesses such as epilepsy, hypothyroidism or celiac disease, and others don not. The first possible reason is the difference in the genes that are triplicated. Genes can come in different alternate forms, called "alleles-. The effect of over expression of genes may depend on which allele is present in the person with trisomy 21.
