Apanemia Health Centre

Archive for the ‘Down Syndrome’ Category

There are three main types of chromosomal abnormalities in Down syndrome:

a) The vast majority of children with Down syndrome (about 95%) have an extra chromosome 21. Instead of the normal number of 46 chromosomes in each cell, the individual with Down syndrome has 47 chromosomes. This abnormality known as Trisomy 21.

b) The second type is called translocation since the extra chromosome 21 is linked or translocated on another chromosome, usually chromosome 14, 21 or 22. If translocation is found in a child with Down syndrome is important to examine the chromosomes of the parents since at least one third of cases, a parent may be the carrier of the translocation. This form of chromosome error is between 3 and 4% of individuals with Down syndrome. Read the rest of this entry »

Down syndrome is a major cause of mental retardation in the world. It is a chromosomal abnormality that causes delays in physical and intellectual development. It is known that one of every 800 to 1000 births is usually affected by this problem.

Also, the statistics tell us that 80% of children born to women under age 35. There is wide variation in physical development, behavior and mental abilities. Most people with Down Syndrome in the range between mild and moderate mental retardation.

Down syndrome was first described in 1866 by John Langdon Down. In 1959, genetic analysis allowed Dr. Jerome Lejeune determine the cause of Down syndrome. People tiene2 copies of each of the 23 chromosomes. Read the rest of this entry »