Monogenetic Inheritance


Monogenetic inheritance are genetic conditions that arise from the mutation of a single gene and are generally inherited in a specific pattern. When a physical characteristic is dominated by a single gene, its properties will be subject to the characteristics of the alleles. For the physical attributes that are subject to a single gene, when it has more than two types of alleles, it is possible to determine the probability that each allele presents to be transferred to the offspring.

Monogenetic inheritance is the cause of the manifestation of the following diseases:

  • Autosomal Dominant Inheritance: this determines that the individual only requires an abnormal gene, from one of the parents, to receive the disease. In this case, it is enough for a single abnormal gene to be present on one of the chromosomes of either parent to cause the disease, even when the parallel gene of the other parent is natural.

    Certain criteria must be met for a disease to be transferred by the autosomes and to proceed in a dominant way: that the character is manifested in each generation. That the two sexes come to affect each other equally. The person who does not present the genetic alteration does not transfer the character. Among the dominant hereditary diseases is neurofibromatosis.

  • Autosomal recessive inheritance: there are certain diseases that are transferred in a recessive manner. This means that a person must inherit two mutated copies of a single gene (one copy from the mother and one from the father) to get the disease. Now, if the person inherits a normal copy of the gene and a mutated one, the person will be more likely to be healthy, but will be a carrier since the normal copy of the gene will compensate for the mutated one. Among the recessive hereditary diseases are: sickle cell anemia, cystic fibrosis and Tay-Sachs disease.
  • Inheritance added to the X chromosomes: it is good to mention that women have two copies of the X chromosome (XX), which means that if any of the genes of said chromosome comes with an alteration, the other, which is normal, will compensate the copy that is altered, causing the woman to be healthy, but a carrier of the X chromosome-associated condition.

Men, on the other hand, have one X and one Y chromosome (XY), so if any of the genes that make up the X chromosome undergoes any variation, it will not have another copy to compensate for it, this means that the probability of transmitting the disease is extremely high. Some of the diseases related to this inheritance are: muscular dystrophy and hemophilia