Inheritance and what causes down syndrome.
In most cases Down Syndrome results from faulty gamete cell division and are not inherited. A small percentage of those with Down Syndrome did inherit the chromosomal defect from the mother or father. Down Syndrome is caused because of an excess of chromosome 21. 95% of people with the disease have a complete extra chromosome 21 and 4% have it located onto another chromosome, usually 14.
There are two types of prenatal testing.These two types are screening tests and diagnostic tests. Types of screening tests include nuchal translucency testing, the triple screen,and a detailed ultra sound. Types of diagnostic testing are aminocentesis,chorionic villus sampling, and percuntaneous umbilical blood sampling.
Testing and Screening
