Down Syndrome is a chromosomal abnormality-induced disease commonly known as Down's syndrome. Children with Down Syndrome often display distinct physical features, including wide-set eyes, a flattened nasal bridge, small eye slits, upward slanting outer eye corners, epicanthic folds, small ears, a protruding and often protruding tongue, excessive drooling, short stature, a smaller-than-normal head circumference, a shortened anteroposterior diameter, a flattened occipital region, a short neck, loose skin, delayed and often misaligned tooth eruption, fine and sparse hair, delayed closure of the anterior fontanel, and a possible third fontanel along the parietal-occipital midline. Their limbs are short, and due to ligament laxity, their joints can be excessively flexible. Their fingers are thick and short, with the middle phalanx of the little finger often hypoplastic, resulting in an inward curvature. The metacarpal bones are short, and the palmar triradiate is shifted distally. Common features also include a single palmar crease and sandal gap toes. The thumb ball of approximately half of these children exhibits an arcuate skin pattern.
These children often exhibit lethargy and feeding difficulties. Their intellectual impairment becomes increasingly apparent as they age, with IQ scores ranging from 25 to 50. Both motor and sexual development are delayed. Males with Down Syndrome do not have fertility even when they reach puberty. In contrast, female patients may have menstrual cycles and potential fertility. These children often suffer from congenital heart disease and other malformations. Due to their weakened immune systems, they are prone to various infections, and their risk of developing leukemia is 10 to 30 times higher than the general population. If they survive into adulthood, they often develop symptoms of Alzheimer's disease after age 30.
