1.1 BACKGROUND OF STUDY
Down syndrome is a genetic disorder caused when abnormal cell division results in an extra chromosome 21.
This genetic disorder, which varies in severities cause lifelong intellectual disability and developmental delays and in some people it causes health problems.
Down syndrome is the most common genetic chromosomal disorder and cause of learning disabilities in children.
Better understanding of Down syndrome and early intervention can greatly increase the quality of life for children and adults with the disorder and help them live fulfilling lives; although it has no cure (Mayo Clinic, April 19, 2014).
This syndrome took its name from John Langdon Down, an English physician who in the late 19th century was able to publish an accurate description of a person with this syndrome hence the name Down syndrome.
There are certain characteristics associated with this syndrome such as:
· Low muscle tone
· Small stature
· An upward slant to the eyes
· A single deep crease across the centre of the palm
· Flattened facial profile
· Heart problem
· Respiratory problems among others.
It is more than 75 years now, since maternal age effect in Down syndrome was discovered and 50 years since the genetic background in Down syndrome involving an extra chromosome 21 material was identified.
Down syndrome is a genetic syndrome occurring in from 1 in 650 to 1 in 1000 live births. In 95% of cases, Down syndrome is caused by non-disjunction during cell division, with mothers contributing the extra chromosome in 85% cases. When this disjunction occurs after fertilization it leads to Down syndrome where one line of cells in the developing fetus contains an extra copy of chromosome 21 and the second line of cells in the developing fetus does not.
Risk for Down syndrome is associated with maternal age. Children with Down syndrome are impaired in verbal processing and expressive language (Fidler, 2008).
In recent years between the 19th century and the 20th century the number of babies born with Down syndrome increased about 30%. Older mothers are likely to have babies affected by Down syndrome than younger mothers. In other words the prevalence of Down syndrome increases as the mother’s age increases.
The actual cause of this syndrome is idiopathic although, maternal age and paternal age are factors that have been linked to an increased chance of having a baby with this syndrome. However due to higher birth rates in younger women which could also be a predisposing factor, 80% of children with Down syndrome are born to women who are advanced in age.
The additional partial or full extra chromosome 21 can originate either from the mother or father. Approximately 5% of cases have been traced to the father. Down syndrome is no respecter of race or economy.
In Down syndrome,only 1% of all cases occur as a result of translocation (hereditary) it occurs sporadically and maternal age cannot be linked to the risk of translocation.
The risk of a mother having a baby with Down syndrome rises dramatically after she reaches 35 years of age.
A woman is born with all of the eggs (ova) she will ovulate with for the rest of her life. So if one is 30 years when one conceives, then the egg (ova) one conceived with is also 30 years old; this is applicable to all age group over 35 years. As the eggs (ova) age, the more likely they are to have errors that can result in trisomies including trisomy 21 (Down syndrome) (Kathleen, 2016).
Advanced maternal age is a risk factor for Down syndrome. This risk factor reaches 3.6% of live births when mother’s age is around 44 years. It cannot be prevented but can be detected before the child is born.
A woman’s chance of giving birth to a child with Down syndrome increases with age because older eggs (ova) have a greater risk of improper chromosome division (Mayo Clinic, 2014).
As a woman ages, her fertility that is, the chance she will get pregnant is reduced. On average, this decline begins slowly in the early thirties and speeds up in the late thirties and forties (Rowe, 2008).
1.2 STATEMENT OF PROBLEM
The researcher observed that more often than not, more children are coming down with trisomy 21, especially to mothers who are elderly (advanced in age).However, ignorance tends to play a major role. Hence the researcher wants to investigate on the relationship between advanced maternal age and Down syndrome and the possible ways of creating awareness because this syndrome predisposes babies born to advanced mothers to numerous pathological disorders.