What is the Difference Between X linked and Y linked Inheritance

The key difference X linked and Y linked inheritance is that in X linked inheritance, the gene causing the trait or disorder is located on the X chromosome, while in Y linked inheritance, the gene causing the trait or disorder is located on the Y chromosome.

Some genetic conditions are due to variants in a single gene. These variants are also known as mutations. These genetic conditions are inherited in one of several patterns. This depends on the gene involved. There are several patterns of inheritance such as autosomal, X linked, Y linked, codominant or mitochondrial. X linked and Y linked inheritance are two patterns of inheritance of genetic conditions.

CONTENTS

1. Overview and Key Difference
2. What is X linked Inheritance
3. What is Y linked Inheritance
4. Similarities – X linked and Y linked Inheritance
5. X linked vs Y linked Inheritance in Tabular Form
6. Summary – X linked vs Y linked Inheritance

What is X linked Inheritance?

X linked inheritance refers to a situation in which the gene that causes the trait or disorder is located on the X chromosome. When there is a mutation in one copy of a gene, this can cause disease. This is because the gene cannot communicate the correct instructions to the human body. X linked genetic condition is caused due to a mutation in a gene on the X chromosome. This inheritance pattern is mainly divided into two types: X linked dominant, and X linked recessive.

In X linked dominant inheritance, a single copy of the mutation is enough to cause the genetic condition in both males and females. Fathers cannot pass X linked dominant genetic conditions to their sons. However, all daughters of the affected fathers will be affected by the genetic condition and can pass it on to their children. Some examples of X linked dominant genetic conditions are Goltz syndrome, Aicardi syndrome, X linked dominant porphyria, Rett syndrome, etc.

In X linked recessive inheritance, both copies of the gene should be mutated to cause a genetic condition. Females can get an X linked recessive disorder, but it is very rare since females have two X chromosomes. Males are predominately affected by X linked recessive inheritance since they have only one X chromosome. Some examples of X linked recessive genetic conditions are red-green colour blindness, haemophilia A, Duchenne muscular dystrophy, X linked ichthyosis, glucose 6 phosphate dehydrogenase deficiency.

What is Y linked Inheritance?

Y linked inheritance refers to a situation in which the gene that causes the trait or disorder is located on the Y chromosome. Normally, a condition is known as Y linked if the altered gene that causes the genetic condition or disorder is located on the Y chromosome. The Y chromosome is one of the two sex chromosomes in each of a male’s cells. As only males have a Y chromosome, Y linked inheritance is only observed in males. The variant or mutation can only be passed from father to son in Y linked inheritance.

Y linked inheritance can be difficult to detect. This is because the Y chromosome is smaller than the X chromosome and autosomal chromosomes. It also has about 200 genes. Some examples of Y linked genetic conditions are Y chromosome linked infertility and some cases of Swyer syndrome.

What are the Similarities Between X linked and Y linked Inheritance?

• X linked and Y linked inheritance are two patterns of inheritance of genetic conditions.
• In both patterns of inheritance, the affected gene is on the sex chromosomes.
• They are sex-specific patterns of inheritance.
• Different genetic disorders are inherited by using both patterns of inheritance.
• They are vital mechanisms in evolution.

What is the Difference Between X linked and Y linked Inheritance?

X linked inheritance means that the gene causing the trait or disorder is located on the X chromosome while Y linked inheritance means that the gene causing the trait or disorder is located on the Y chromosome. So, this is the key difference between X linked and Y linked inheritance. Furthermore, the genetic conditions inherited through X linked inheritance can be observed in both males and females. But, on the other hand, the genetic conditions inherited through Y linked inheritance can only be observed in males.

The below infographic lists the differences between X linked and Y linked inheritance in tabular form for side by side comparison.

Summary – X linked vs Y linked Inheritance

X linked and Y linked Inheritance are sex-specific patterns of inheritance of genetic conditions. The disease-causing gene is located on the X chromosome in X linked inheritance. Similarly, the disease-causing gene is located on the Y chromosome in Y linked inheritance. Thus, this is the summary of the difference between X linked and Y linked inheritance.

Reference:

1. “Inheritance Patterns.” Understanding Genetics: A New York, Mid-Atlantic Guide for Patients and Health Professionals., U.S. National Library of Medicine, 8 July 2009.
2. “Y-Linked Inheritance – Definition and Examples.” Biology Articles, Tutorials & Dictionary Online, 28 June 2021.

Image Courtesy:

1. “Figure 13 01 05” By CNX OpenStax – (CC BY 4.0) via Commons Wikimedia

2. “Y-linked” By File:Autosomal dominant – en.svg: Domaina, Angelito7 and SUM1Derivative work: SUM1 – Based off of File:Autosomal dominant – en.svg (CC BY-SA 4.0) via Commons Wikimedia