transmission patterns of single gene

Autosomal dominant:

At least one parent is affected. Can affect both males and females. Every child has a 1 out of 2 chance of having the disease. Can result from a spontaneous mutation.

Autosomal recessive:

Both parent have the recessive gene. 1 in 4 chance of having disease, 2 in 4 chance of carrying the disease, 1 in 4 of being normal.

X-linked dominant:

An affected female will transfer the disease to half her sons and half her daughters. An affected male will transfer the disease to all his daughters but none of his sons.

X-linked recessive:

Most X link disorders are recessive. Offspring of carrier mom: for daughters, 1 out of 2 are normal, 1 out of 2 are carriers. Males have 1 out of 2 chances to have the disease, 1 out of 2 of being normal. An affected male does not transmit the disease but all daughters are affected.

Mitochondrial:
This type of inheritance, also known as maternal inheritance, applies to genes in mitochondrial DNA. Because only egg cells contribute mitochondria to the developing embryo, only females can pass on mitochondrial conditions to their children.

Codominant:
In codominant inheritance, two different versions (alleles) of a gene can be expressed, and each version makes a slightly different protein.