Sunday, January 29, 2012

What is Trisomy

Trisomy 21

                 Trisomy is a condition when a baby is born with one more chromosome than  normal. there may be three or more copies of the chromosome rather than the expected two copies. It is usually caused by the failure of a pair of homologous chromosomes to separate during meiosis, Can also be due to  a translocation mutation.

 Most organisms that reproduce sexually have pairs of chromosomes in each cell, with one chromosome inherited from each parent. In such organisms, a process called meiosis creates cells called gametes (eggs or sperm) that have only one set of chromosomes. The number of chromosomes is different for different species. Human beings have 46 chromosomes (i.e. 23 pairs of chromosomes). Human gametes have only 23 chromosomes.
If the chromosome pairs fail to separate properly during cell division the egg or sperm may have a second copy of one of the chromosomes.  If such a gamete results in fertilization and an embryo, the resulting embryo may also have an entire copy of the extra chromosome.

The most common type of Trisomy

Trisomy 21 or Down's Syndrome -  is a chromosomal condition characterized by the presence of an extra copy of genetic material on the 21st chromosome. The incidence of Down syndrome is estimated at 1 per 733 births.More common among older parents due to increased mutagenic exposures on their reproductive cells. Other factors may also play a role. Down syndrome occurs in all human populations regardless of race and location.

Risk factors: 
Advancing maternal age
. - increase with age because older eggs have a greater risk of improper chromosome division.

Having had one child with Down syndrome. Typically, a woman who has one child with Down syndrome has about a 1 percent chance of having another child with Down syndrome.

Being carriers of the genetic translocation for Down syndrome. Both men and women can pass the genetic translocation of the defect on to their children

More: How is Down Syndrome Diagnose?

Common Complications: 

Heart defects. Approximately 50%  develop some form of heart defect. Some may require heart surgery.

Leukemia. They have a higher chance of developing leukemia in later parts of their life.

Infectious diseases. Abnomalities to the immune system makes them susceptible to all kinds of infectious disease.

Dementia. Symptoms usually appear before 40 and have a higher rate of seizure.

Sleep apnea
. soft tissue and skeletal alterations can sometimes obstruct airways making them at risk of obstructive sleep apnea.

Obesity. higher chances of getting obese

Other problems. Down syndrome may also be associated with other health conditions, including gastrointestinal blockage, thyroid problems, early menopause, seizures, hearing loss, premature aging, skeletal problems and poor vision.
Life Expectancy:   Depending on severity . Some have lived 50 and beyond

Treatment:  There is no treatment for down's syndrome.  Early intervention programs are available to stimulate motor, cognitive, and developmental skills to help the child cope up with his environment.  

Coping and support 

  • Find a team of trusted professionals. You'll need to make important decisions about your child's education and treatment. Build a team of doctors, teachers and therapists you trust. These professionals can help evaluate the resources in your area and help explain state and federal programs for children with disabilities.
  • Seek out other families who are dealing with the same issues. Most communities have support groups for parents of children with Down syndrome. You can also find Internet support groups.
  • Don't believe misinformation about Down syndrome. Some people believe that children with Down syndrome must be placed in segregated special education schools and that adults with Down syndrome usually live in institutions. Not true. Many of them  live with their families or independently, go to mainstream schools, read and write, have jobs and live fulfilling lives

Down Syndrome Parenting on Amazon

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