Degrees of Consanguinity Calculator

What is Consanguinity?

Consanguinity refers to the relationship between two individuals who share a common ancestor. The degree of consanguinity measures how closely related two people are based on their shared genetic lineage. This concept is particularly important in genetics because it affects the likelihood of inheriting certain genetic disorders.

The degrees of consanguinity are typically measured in terms of the number of generations between the two individuals and their shared ancestor. For example, siblings share a consanguinity degree of 1, parents and children share a degree of 1, and first cousins share a degree of 2.

How to Calculate Degrees of Consanguinity

The degree of consanguinity between two individuals can be calculated by determining the number of generations between them and their most recent common ancestor. Here's a step-by-step method:

1. Identify the two individuals whose relationship you want to determine.
2. Find the most recent common ancestor (MRCA) of the two individuals.
3. Count the number of generations from the MRCA to each individual.
4. The degree of consanguinity is the sum of these two generation counts.

For example, if Person A is 3 generations removed from the MRCA and Person B is 2 generations removed, the degree of consanguinity would be 3 + 2 = 5.

Examples of Consanguinity Degrees

Here are some common examples of consanguinity degrees:

• Siblings: Degree 1 (both are 1 generation removed from their parents)
• Parent and Child: Degree 1 (one generation apart)
• First Cousins: Degree 2 (each is 1 generation removed from a common grandparent)
• Second Cousins: Degree 3 (each is 1 generation removed from a common great-grandparent)
• Aunt/Uncle and Niece/Nephew: Degree 2 (aunt/uncle is 1 generation removed from grandparent, niece/nephew is 2 generations removed)

These examples illustrate how the degree of consanguinity can vary based on the relationship between two individuals.