As estimated by the CDC, one out of every 200 live births suffers from some type of chromosomal disorder. A mother’s age at the time of pregnancy is often part of the cause of this genetic abnormality. It is also estimated that, out of all recorded conceptions, 15 percent ended in a spontaneous abortion or miscarriage. Out of that number, it is believed that 60 percent were the direct result of defects or chromosomal disorders.
What Is a Chromosomal Disorder?
A chromosomal disorder is a condition where a person’s chromosomes are abnormal. Each person has 23 sets or pairs of chromosomes for a grand total of 46. A chromosomal disorder occurs when any of those chromosomes are altered, defective, missing or duplicated.
Chromosomes and genes work together to create the form and physical characteristics of a human being. While they are not the same thing, they are grouped together in the same category because they both primarily do the same thing, only genes are much more precise. They are both considered to be genetic factors that contribute to a person’s physical make up.Whenever there is a disruption in the body’s form or function that is directly related to a specific chromosome, a chromosomal disorder occurs.
Examples of Chromosomal Disorders
The following list of chromosomal disorders will help to provide an understanding of what chromosomes are primarily responsible for:
Down Syndrome is one of the most common known chromosomal disorders. Individuals diagnosed with Down Syndrome have an extra chromosome. While they have several physical problems such as short stature, thick lips, protruding tongue and gaps between both fingers and toes, they are also predisposed to several different health problems and various levels of mental retardation. They run an exceptionally high risk of heart disease as well as a compromised immune system that can to lead to an increase in infection and illness. Down Syndrome can occur in as many as one of every 700 to 1,000 births.
Turner Syndrome only affect girls and occurs once in every 2,500 to 5,000 births. Girls must have 2 X chromosomes. Those with Turner Syndrome only have one. Their physical characteristics may include short stature, broad chest, webbed neck and abnormal sexual development. Hormone therapies may help to relieve some of these symptoms, but they will not correct them all. Special learning techniques that involve spatial and visual techniques may help them to overcome some of the learning issues they may experience as a result of this type of condition.
Occurs in 1 out of every 10,000 to 25,000 births and results in developmental delays and possible obesity. Children born with a defective 15th chromosome may also have some degree of mental retardation. They may remain short and have abnormally small feet and hands.This specific disorder can also lead to mental behaviors such as acting out, hoarding food and becoming overly aggressive.
Allows for the development of both benign and malignant tumors in and near the central nervous system. The condition can range from mild to severe and can lead to various levels of learning and physical disabilities if the tumors grow near the spine.
Occurs in 1 out of every 15,000 births. The child is unable to produce the enzyme responsible for breaking down phenylalanine. Excessive amounts of phenylalanine can result in seizures, delayed behavior and motor function, eczema and mental retardation. In most cases, restricting it from the diet will allow the child to develop normally.
Extra Chromosome Disorders
Disorders like Down Syndrome that involve an extra chromosome are not rare. In fact, Down’s is thought to be the most common birth defect. While the addition of the extra chromosome causes the disorder, there is little to be found that proves why the level of impairment is so drastically different from person to person. Some Down’s patients are extremely high function and live a fully normal life. They may get married, and in some cases, have children of their own. Other patients experience severe heart conditions and mental retardation that makes living on their own virtually impossible.
Another condition that falls under the category of sex chromosome disorders would be Klinefelter Syndrome or XXY Syndrome. This condition affects males and is the result of the child having an extra X chromosome. The extra X or female chromosome can hinder the development of a male child’s sexual organs and also prevent the testes from functioning efficiently. The testes produce male hormones that work to counteract female hormones.
The human body is designed to produce both male and female hormones, no matter what gender a person is. The difference being that males produce more testosterone, and women produce more estrogen or female hormones. Basically, it is nature’s way of creating balance. If a male child does not have the capability of releasing adequate amounts of testosterone, they may begin to exhibit various female features, such as a higher pitched voice and little to no body hair.
There are several different tests that can be performed on a mother to determine if the fetus has a chromosomal disorder. While this can be an advantage when preparing for adequate health and prenatal care, it also has a downside. It is estimated that over 90 percent of all women who are told they will give birth to a child who has an abnormality will abort the fetus before it is born. When a child is still in the womb, the level of their impairment can only be estimated. Their true level of disability will not be known or even realized until they have been born.
Many children who have a genetic disorders can lead lead a full and productive life – the primary factors being how they are cared for and what opportunities they are given to excel. It has been proven that Down Syndrome children with mild to moderate retardation can still lead full and active lives. The majority of parents who learn of the possibility of a chromosomal disorder will often abort the fetus to avoid having to deal with the extra care and cost the birth of the child will entail.
Health Problems Caused by Chromosomal Disorders
It has been determined that many fetuses who have chromosomal defects will often be aborted before they begin to mature into a child’s form. There are stillborn cases due to chromosomal defects. It is uncertain why some children with these types of defects are miscarried, while others are born with varying degrees of disabilities.
Disabilities can be both physical or mental in nature. Chromosomal defects affect how the body is constructed, so it goes without saying that they would also affect how the child develops once they are born. Physical abnormalities can be widely varied as well. Some children are born with heart defects, unusual physical features or immature reproductive organs.
Children with mental health problems that result from chromosomal disorders vary in the severity of their cases. Some may have very mild mental retardation, while others have trouble communicating in even the simplest of ways. There are many cases, such as with Prader-willi patients, in which it is hard to see a physical abnormality other than the obesity. It is often their behaviors that are a direct indicator that something else is wrong. Once a child is born, doctors can perform more stringent tests to determine exactly what is happening within the child’s body to cause their specific health issues.