By: Patricia Raczak
Down syndrome was first was first published by an English doctor, John Langdon Down. Although he did not know what caused it he was the first one to describe a patient in 1866. By the 20th century medical science had improved and a French doctor Jerome Lejeune identified the 21st chromosome.
Down syndrome, or Trisomy 21, as it is called within the medical community, is caused by an extra copy of the 21st chromosome (Down Syndrome Research and Treatment Foundation Online). A normal person is born with 46 chromosomes, but when an extra copy is formed causing a person to have 47 chromosomes, Down syndrome is formed. The reason for this error of cell division is still unknown. Down syndrome is chromosomal mutations that cause defects in a child. The importance of learning about this topic is to understand the body and chromosomes, and why these defects occur. Despite the various types of Down syndromes the characteristics are quite the same. The results of down syndrome are often seen with distinct facial characteristics such as oblique eye fissures with epicanthic skin folds on the inner corner of the eyes, muscle hypotonia (poor muscle tone), a flat nasal bridge, a single palmar fold, a protruding tongue (due to small oral cavity, and an enlarged tongue near the tonsils), a short neck, white spots on the iris known as Brushfield spots, excessive joint laxity including atlanto-axial instability , congenital heart defects, excessive space between large toe and second toe, a single flexion furrow of the fifth finger, and a higher number of ulnar loop dermatoglyphs (Wikipedia Online). Another result of Down syndrome is the mental
retardation of the child. As a result of the retardation a child would need life long care or assistance in living its life.
Down syndrome is the most...