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Causes of Genetic Disorders


The human body contains 46 chromosomes in total that exist in 23 pairs. Genetically an individual inherits these chromosomes from both his mother and his father. If one or more of these chromosomes mutates or changes, it can result in a genetic disorder. Some of the common causes of genetic disorders include:

  • Heredity: In most cases, genetic disorders are inherited from the parents. If one or both parents have a mutated gene, there is a definite possibility of it being passed on to the children. Some disorders are caused by a combination of mutated genes from both parents while others may be the result of a mutated gene from only one parent.
  • Dominant and Recessive Factors: Dominant factors are a cause of genetic disorders when the mutated gene comes from a single parent. On the other hand, recessive factors cause genetic disorders when every copy of the gene is affected. If such a recessive factor is inherited from only one parent, the child will be only a carrier but if both parents have passed on the recessive factor, the child will inherit the disease.
  • X-linked Factors: Gene mutations associated with the X-chromosome cause genetic disorders. The X chromosome determines gender. Men have an X and Y chromosome whereas women have two X chromosomes. This is the reason why men are more affected by x-linked factors as compared to women. Genetic disorders like Duchenne muscular dystrophy are caused by these kinds of X-linked factors.
  • Environmental Causes: Certain genetic disorders are caused because of exposure to certain environmental factors. Studies show that even though certain people are at a higher risk of developing disorders like cancer, the activation of the disease will not happen without the influence of certain environmental factors. For example, genetic disorders like heart disease will mostly manifest in the presence of external factors like unhealthy diet and lack of physical exercise.
In addition to the above-mentioned causes, certain risk factors may also increase the likelihood of an individual developing a genetic disorder. Some of the known risk factors of genetic disorders include:

  • Family History: If an individual has a family history of a particular genetic disorder, he is more likely to develop it himself. This is mainly because of his inherited genetic makeup. In most cases, if a couple has a child with a genetic disorder like Down syndrome, it increases the risk of them having another child with the same condition.
  • Age: The age of the mother in particular also plays a vital role in increasing the risk of genetic disorders. The risk of genetic disorders caused by chromosomal abnormalities is usually higher in children born to women who are over the age of 35 years. In cases of disorders like Alzheimer’s disease, the risk always increases with progressing age.
  • History of Miscarriages: If a woman has had several miscarriages in the past, there is a higher risk of her giving birth to a baby with a genetic disorder because of chromosomal abnormalities. In such cases, the miscarriages could be the result of genetic abnormalities in one or both parents.
  • Parental Blood Relation: Studies show that in certain cases where there is even a distant blood relation between the father and mother, the child is more likely to develop a genetic disorder. Certain ethnic and geographic communities practice marriage between close relatives. This increases the chances of their children developing some type of genetic diseases.

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