Polygenic And Multifactorial Inheritance In Environmentalism

Polygenic and multifactorial inheritance in environmentalism

In this bibliographic review we will deal with polygenic inheritance and multifactorial inheritance, in order to obtain a more optimal understanding we will establish the difference between these two types of inheritance before entering more in detail in each of them.

Many articles establish that polygenic heritage and multifactorial heritage are synonyms, however, after investigating several texts it was established that this is false, since these have a difference with regard to the distribution of the phenotype;The polygenic inheritance shows a continuous distribution and multifactorial inheritance does not present this type of distribution. The continuous distribution is generally represented by the Gauss bell.

Taking into account this difference we will continue to explain the concept and characteristics of each of them.

Polygenic inheritance

Type of inheritance in which several genes are involved without environmental influence, as mentioned by Nussbaum, Mcinnes, and Williard (2016) in this type of inheritance in which they interact gen-GEN they can simply be additive or much more complicated. For a polygenic inheritance there is not only black and white, we also find nuances.

A polygenic inheritance is a non -Mendelian inheritance Raby (2019) that means this, that here we can find both incomplete dominance and codominance.

To better understand we will explain it with example: as we know dyslexia is the alteration in the ability to read, confusing the order of words, syllables or letters.

In the image we observe a distribution curve or the Gauss bell, and here we can observe how there is a population distribution along the curve;At the far left we find that 20% of the population presents the disease (dyslexia), in the extreme right we have 20% of the population with a very precise and fast reading capacity and in the middle we are found to the majorityof the population (60%) which do not present dyslexia or an overlapping and fast reading capacity.

There are various characteristics not only diseases that present this type of inheritance, some examples are: size, blood pressure, body mass index, intelligence, eye color, etc.

According to Turnpenny and Ellard (2017) there is a possibility to demonstrate through a normal distribution that a phenotype is determined by a polygenic inheritance in which each of the genes will have a similar additive effect.

It is more likely that in first -degree relatives the polygenic inheritance shows more than in farthest relatives of kinship (Turnpenny and Ellard 2017).

Multifactorial inheritance

As Raby (2018) mentions in its article, multifactorial heritage also called complex disease due to the interaction of multiple genes and various environmental factors, for this reason, a multifactorial heritage is a non -Mendelian inheritance Raby (2019).

The factors that influence the development of a multifactorial disorder, both genetic and environmental, are usually considered as predisposition or risk level (Turnpenny and Ellard 2017).

Based on the concept of predisposition we can conclude that the more serious the disease of the affected individual is and the more relatives are affected, the greater the level of risk for that disease in the family (Nussbaum, Mcinnes, andWilliard 2016).

There are several diseases and characteristics associated with multifactorial inheritance, some of them are: schizophrenia, depression, diabetes mellitus, Alzheimer’s disease, Crohn’s disease, etc.

To understand more thoroughly we will explain with the example of coronary arterial disease;There are several genetic predispositions that raise the level of risk of suffering from an EAC such as HTA, thrombosis, atherosclerotic plates, hyperlipidemia or hypercholesterolemias among others, but in turn, there are several predisposing environmental factors such as stress, lack of exercise, a bad badDiet, among others. With this example it can be deduced that an EAC has both genetic and environmental influence.

This type of inheritance is responsible for most diseases;It is worth mentioning that family aggregation in this type of disease does not follow any characteristic pattern (Nussbaum, Mcinnes, and Williard 2016).

To conclude, both polygenic inheritance and multifactorial heritage are of a non -Mendelian nature, therefore they are considered complex inheritances, these two types of inheritance are often used as synonyms due to their similarity, however, it is important to recognize the differencesthat each of them has to provide a more optimal diagnosis and treatment plan to the affected individual and correctly guide the family of the same.

Bibliography

• National Genome Research Institute. (2018). Retrieved on October 19, 2019, at https: // www.Genome.Gov/Search?TURS = multifactorial
• Nussbaum, r., Mcinnes, r., And Williard, H. (2016). THOMPSON AND GENETIC THOMPSON IN MEDICINE (8th ED.). Barcelona: Elsevier.
• Raby, b. (2018). Basic Principles of Genetic Disease. In a. Slavotinek (ed.) and j. Tirnaur (ed.), Uptodate. Retrieved on October 19, 2019, from https: // www-uptodate-com.virtual library.You.Edu.EC/CONTENTS/BASIC-PRINTILES -OF-GENETIC-DISEASE?Search = multifactorial%20heritance & source = search_result & selected = 4 ~ 150 & usage_type = default & display_rank = 4
• Raby, b. (2019). Inheritance Patterns of Monogenic Disorders (Mendelian and Non-Mindelian). In a. Slavotinek (ed.) and j. Tirnaur (ed.), Uptodate. Retrieved on October 19, 2019, from https: // www-uptodate-com.virtual library.You.Edu.ec/content?SEARCH = Multifactorial%20heritance & Topicref = 15540 & source = see_link
• Turnpenny, p., And Ellard, S. (2017). Frequent diseases, polygenic and multifactorial genetic. EMEY ELEMENTS OF MEDICAL GENETICS (15va ed., pp. 129 – 137). Barcelona, Spain: Elsevier.