Down syndrome is a chromosomal abnormality in which individuals have an extra copy of chromosome 21. This remains the most common chromosomal abnormality in humans since the discovery of these diseases. According to literature, there are a number of chromosomal abnormalities, but most of them are not compatible with life. Thus, babies who have these abnormalities either die in their mother’s womb or shortly after birth. This explains the high number of still deaths as well as natural abortions that occur among women. Down syndrome is generally associated with delayed physical growth as well as cognitive ability right from birth. What is quite characteristic about babies with Down syndrome is the set of facial features that essentially make them look the same. One would wonder why babies not related by blood would resemble so much! Babies with Down syndrome develop a low IQ making them to lag behind in class, and some time forced to drop out all together. While normal human have been shown to have an IQ of 100, young adults with Down syndrome have IQ of around 50. It usually presents as a severe form of intellectual disability that is incurable given that it is genetic. This stems from the abnormal growth of the nervous system which transmits impulses from various parts of the body to the brain for coordination. This delays particularly because the nerves are underdeveloped and therefore slow. As a result of this slow pace of transmission, it become very difficult for the brain to learn because learning involves quick coordination of information in such a way that the body is able to draw a meaning from them within the shortest time possible. Physical development is also affected because hormonal communication in the body is impaired and thus coordinated control of growth not possible (Will 2012).
The congenital abnormality is divided into different types depending on how the third copy of chromosome 21 was achieved. These are full Down syndrome, translocation type of Down syndrome and mosaic Down syndrome. Full Down syndrome denotes a congenital anomaly in which all cells in the body possess an extra chromosome 21. This implies that the features will be more pronounced as compared to the other forms given that chromosomal expression is also strong. In fact, this is the most common form that presents in human, according to medical research. Essentially, this means that all cells in the body will then have 47 chromosomes in the body. Mosaic Down syndrome is slightly different in the sense that the body possesses different types of cells. In fact, this is the reason why it is called mosaic Down syndrome. In this type of Down syndrome, some cells in the body remain normal while others will be affected. For instance, while some cells will have the normal chromosomal number of 46, some will have 47 due to the extra chromosome 21. It is the mix-up that makes it known as mosaic form of Down syndrome. It is not as common as the full type, though incidences have been recorded in Asia and Africa. Translocation Down syndrome is quite unpopular as it occurs in just 4% of the cases. It occurs such that the extra chromosome does not exist as a full chromosome. Instead, part of it is translocated to other normal chromosomes. Normally, part of the chromosome is translocated to chromosome 14. In terms of severity, full Down syndrome is the most severe because it involves all the cells in the body. This implies that the extent of physical impairment will be immense in proportion to the number of cells affected. On the other extreme will be translocation, which in addition, has abnormal expression in the body (Green 1997).
Due syndrome is a random occurrence in the body that is initiated at the time of formation of reproductive cells, either the male or female reproductive cells. Generally, there is not particular cause of the abnormality of humans, but rather purely a matter of chance. For example, babies with Down syndrome usually occur together with normal babies in the same families. This implies that nothing can be said to have caused it of parental genetics. In fact, in most cases, it results from subsequent births after normal births have been witnessed in the family. However, it has been noted that the frequency of occurrence of the abnormality seems to rise with maternal age. This is particular due to the fact that abnormalities result from simple parental abnormalities or mutations that accumulate in the body over time. Because female reproductive cells are only produced at puberty and stay for one’s entire life, they are exposed to several mutagens. Thus, as one’s age advances, chances that congenital anomalies will result increases. This is why children born of elderly mothers are more likely to suffer from congenital anomalies o any nature. In terms of statistics, maternal age seems to play a crucial role in the anomaly. Although younger mother are more likely to have babies than older mothers, the frequency still holds for all cases. It usually appears when a woman decides to get a baby when her age is already advanced. In other instances, Down syndrome occurs when family planning is practiced such that the age difference between one births to another is around ten years. This means that by the time the woman is having the third birth, her age will be significantly advanced, thereby exposing her to the risk of having a baby with a congenital anomaly. Indeed, this is why women are encouraged to have babies early enough in their lives because it is quite uncertain what amount of mutations they accumulate over time, and which may influence their reproductive cells.
It has been noted that some mothers are at a greater risk of giving birth to babies with Down syndrome as compared to others. As earlier noted, age is a significant risk factor in Down syndrome because apparently a woman’s eggs get older with time. When a woman gets to the age of 35, the risk stands at 2% and by 45 the risk is around 5%. This shows how significant a difference of ten years can put a woman at a greater risk of giving birth to babies with anomalies. The only reason why is usually appear that most Down syndrome babies are given birth to by young women under the age of 35 is the fact that most women do not give birth beyond this age. And so, the trend given herein is purely based on scientific research and not merely on the frequency of occurrence. The other risk factor is when a mother has previously had a child with Down syndrome. What happens is that apparently the woman is of advanced age already or has some predisposing factors that make it possible for her to give birth to such a baby. In fact, they have 1% chance that the next child given birth to will have Down syndrome. This is why it is encouraged for mothers who have had one baby with Down syndrome to stop their reproductive lives as it is not safe to continue. As a matter of fact, it is difficult to take care of these babies and it can be more difficult if one mother has more than one of them. In addition, parents who are carriers of the genetic translocation can easily pass it to their children. This is also a significant risk factor given that one may not be aware of its existence (Richards 1980).
Down syndrome can result in several complications in the human body, some of which are very lethal. For example, it has been associated with heart defects of different nature. According to statistics, more than half of children who are born of Down syndrome have been fund to have some form of cardiac defect. Some of these defects could be incompatible with life, therefore requiring timely intervention in order to save the child. For instance, surgery may be necessary at a tender age as it may be the only option for the child to survive. The development of leukemia is also another important complication that is popularly associated with young children with Down syndrome. This is the kind of malignant disease that affects white cells, thereby causing abnormal immunity in the body. It is also associated with non-immune related illnesses that may be fatal. Certain infectious diseases like pneumonia have also proven to be complications of the anomaly. This is particular due to the abnormal immune system that is associated with the disease, especially with regards to the development of leukemia. Eventually, the body becomes severely exposed to infections that can certainly lead to death of the individual. Due to abnormal development nervous system and neural coordination, the disease is associated with dementia. This is a type of condition that is associated with memory lapse such that one cannot remember things quite clearly. In particular, children born of mothers beyond the age of 40 are at a greater risk of suffering from dementia. In addition, this group of children is also likely to suffer from seizures of any nature. Sleep apnea can also result from abnormal growth of the respiratory system apparatus. The body is made in such a way that a slight abnormality can significantly affect the body. Babies who happen to have Down syndrome are likely to have obstructive respiratory disease due to anatomical blockade of their respiratory tracts. The other conditions that can be associated with Down syndrome include obesity, thyroid problems as well as poor visions. These are all related to the abnormal growth in the body.
The incidence of Down syndrome has been shown to increase with maternal age. As the mother advances in age, the incidence of birth to Down syndrome babies. This is why most women fear giving birth when they attain the age of 40. It is basically due to the fear of giving birth to babies who have some kind of anomaly. According to literature, the incidence stands at 1 in 725 at the maternal age of 32 years. At the age of 38, the incidence rises to 1 in 175. However, at 42 years of age, the incidence of Down syndrome babies rises sharply to 1 in 12. This shows how significant age can be in causing the disease. However, most Down syndrome babies are generally born of mothers below the age of 35 as most mothers stop giving birth at 35. In fact, there would be more Down syndrome babies if mothers maintained their reproductive age beyond 40 years of age. It is the high level of education among most women that informs them if the impending risk of abnormal babies. Indeed, no woman would willingly risk giving birth to abnormal babies. It is better to avoid giving birth altogether, instead of the possible stigma on the child.
The tests are generally categorized as either screening tests for mothers or diagnostic tests for babies. Screening tests are used in mothers to identify if they have a significant risk of giving birth to babies with Down syndrome. It basically checks for the existence of translocations involving chromosome 14 given that it bears the most risk. It is done using blood tests at around the 16th week of pregnancy. Blood tests seek to determine the levels of pregnancy associated proteins in blood. Abnormal levels indicate that the baby could be at risk of having Down syndrome. The other risks that have been associated with positive results include spina bifida among other abnormalities. Other tests that have been found to be relevant include ultrasound that is specifically used to measure the size of the baby’s neck. It must be noted that babies with Down syndrome have a larger neck region compared to normal babies (Conor 1999). This is one of the features that causes then to look alike irrespective of genetic dissimilarities between them. In case the results appear suspicious, amniocentesis can be carried out, which basically involves withdrawing a sample of the amniotic fluid for chemical analysis of the genetic structure.
Initially, babies with Down syndrome would only live to the age of 10 years. However, this has since increased significantly with most of them living up to the age of 50. The life expectancy, however, depends on the severity of the disease as well as the associated complications. For example, if the disease present with severe congenital problems, there are very little chances that the baby will survive for long. This is because the cardiac system is such an important thing that one cannot survive it if remains dysfunctional. However, one can live a long life if the problems are only related to neural complications because these do not affect the vital organs. It must be noted that one can survive even with mental instability. The higher life expectancy has also been attributed to the reduced chances of developing cancers like leukemia. Over time, research has been done on this anomaly and ways of controlling certain complications determined (Liptak 2008). Thus, by managing the complications, people’s lives have tremendously been increased. In fact, between 1980 to date, life expectancy has increased from 25 to 50. This is significant in the sense that one no longer needs to worry about their lives even if he or she has Down syndrome.
In conclusion, Down syndrome is a chromosomal abnormality in which individuals have an extra copy of chromosome 21. This remains the most common chromosomal abnormality in humans since the discovery of these diseases. According to literature, there are a number of chromosomal abnormalities, but most of them are not compatible with life. The congenital abnormality is divided into different types depending on how the third copy of chromosome 21 was achieved. These are full Down syndrome, translocation type of Down syndrome and mosaic Down syndrome. Down syndrome can result in several complications in the human body, some of which are very lethal. For example, it has been associated with heart defects of a different nature. According to statistics, more than half of children who are born of Down syndrome have been fund to have some form of cardiac defect. Some of these defects could be incompatible with life, therefore requiring timely intervention in order to save the child. Blood tests seek to determine the levels of pregnancy associated proteins in blood. Abnormal levels indicate that the baby could be at risk of having Down syndrome. The other risks that have been associated with positive results include spina bifida among other abnormalities. Other tests that have been found to be relevant include ultrasound that is specifically used to measure the size of the baby’s neck.