For centuries, Down syndrome, or Trisomy 21, has been alluded to in art, literature and science (Epstein 49). One of the more interesti

Gibbs and Gibbs (1964) depicted bilateral "spike-like" activity over parietal areas in sleep records of DS children and also noted extensive monorhythmic 4/sec waves chiefly frontal and parietal in the waking state. Prominent occipital high voltage 1-2/sec waves with a sharp component in the terminal stage were also stated (Gibbs and Gibbs 1964). “There are no correlations between EEG abnormalities and special clinical features (Neidermeyer 373-374).”

Many theories have been developed, but the actual causative factors of Downs are still unknown. Some doctors believe that immunologic problems, hormonal abnormalities, viral infections, X-rays, or genetic predisposition may be the cause of the improper cell division resulting in trisomy 21 (Yang 185). It has been known for some time that the hazard of having a child with Down syndrome increases with advancing age of the mother; that is to say, the older the mother, the greater the possibility that she may have a child with Down’s syndrome. However, most children with Down syndrome (more than 85 percent) (Vosatka 213) are born to mothers younger than 35 years of age. Some investigators reported that older fathers might also be at an increased risk of having a child with DS. An interesting note about this is that this is only the case for Down syndrome caused by the triplication of chromosome 21; the risk of DS through Robertsonian translocation actually goes down with age. “Again the causes of this are not fully realized, only that the risks for triplication of chromosome 21 seem to be variable and increase exponentially with age, while Robertsonian translocation is a constant variable and seems to be hereditary (Mao 450). Approximately 40% to 50% are familiar in that they are inherited from a cytogenetically balanced parent (Epstien 57).”

The diagnosis of Down syndrome can be done either through physical examination of the newborn, or prenatally through screening and diagnostic tests. The most commonly used screening tests are the Alpha-fetoprotein Plus and the Triple Screen (National DS Society). These tests assess quantities of various substances in the blood (alpha-fetoprotein, human chorionic gonadotropin and unconjugated estriol) and together with the woman's age, approximate her risk of having an adolescent with DS. These screening tests are normally offered between fifteen and twenty weeks of gestation (Kim 506). Screening tests are of limited value and are often performed in conjunction with a detailed sonogram. “These tests are only able to accurately detect about sixty percent of fetuses with Down syndrome (National Down Syndrome Society).” Many women who undergo these tests will be given false-positive readings, and some will be given false-negative readings. The procedures available for prenatal diagnosis of DS are amniocentesis, chorionic villus sampling (CVS), and percutaneous umbilical blood sampling (PUBS).

Some topics in this essay:
Society Amniocentesis, Patricia Jacobs, Tetralogy Fallot, Robertsonian Translocation, PFKL Vosatka, Gibbs Gibbs, England Barbiero, , DS Society, Surrey England, trisomy 21, 21st chromosome, mental retardation, expression cause, triplication 21st chromosome, triplication 21st, cell division, robertsonian translocation, chromosome 21, 21st chromosomes, patients syndrome, genes 21st chromosome, trisomy 21 due, interpeak latency iv-v, chromosomes parent cell,