Iran received $4.2 billion in similar payments under the 2013 interim agreement with the United States and was then given another $2.8 billion by the Obama administration last year in a bid to keep Iran committed to the talks through November, when negotiators parted ways without reaching an agreement.
The DNA in our chromosomes determines how we develop. Down syndrome is caused when there is an extra chromosome. People with Down syndrome have 47 chromosomes in their cells instead of 46. They have an extra chromosome 21, which is why Down syndrome is also sometimes known as trisomy 21. Although we know how Down syndrome occurs, we do not yet know why it happens.
The most common form of Down syndrome is known as Trisomy 21, a condition where individuals have 47 chromosomes in each cell instead of 46. This is caused by an error in cell division called nondisjunction, which leaves a sperm or egg cell with an extra copy of chromosome 21 before or at conception.he only factor known to affect the probability of having a baby with Down syndrome is maternal age. That is, less than one in 1,000 pregnancies for mothers less than 30 years of age results in a baby with Down syndrome. For mothers who are 44 years of age, about 1 in 35 pregnancies results in a baby with Down syndrome.