An abnormality in genetic makeup alters the normal course of development and causes certain dominant characteristics. For instance, in the book Seraph on the Suwanee, Zora Neal Hurston describes the physical defects of chromosomal abnormalities in Earl. Earl's physical defects were described as having an egg-shaped head with practically no forehead and back head. His fingers were like string and too small for his body. His feet were described as being too long and completely flat, with a little lump of flesh under the in-step. Furthermore, his mouth was exceptionally small with the majority it concentrated in the lower lip (67-68). .
Just as Earl's genetic makeup caused certain physical attributes, the chromosomal differences in children with Down's Syndrome causes their own set of physical differences. People with Down's Syndrome often have a face with a flat profile, a depressed nasal bridge and a flat nose. The eyes slant upwards with small skin folds in the inner corner of the eyes. A single deep crease across the palm of the hand is present, along with an outward curvature of the little finger. The ears are slightly smaller. The lips are large and thick and generally very dry. The tongue is much larger in relationship with the size of the mouth and may sometimes protrude. There is often a gap in between the first and second toe. These children may also have low muscle tone and hyper flexibility, which is the excessive ability to extend the joints. These particular physical characteristics usually do not cause any disability to the child; however, during brain formation, varying degrees of mental retardation may result due to the extra genetic information (Pueschel 17). .
Mental abilities and developmental progress varies widely. The majority of .
children with Down's Syndrome function in the mild to moderate range. Some .
may have no mental retardation, while others are profoundly retarded and must .