How does autosomal inheritance differ from X-linked inheritance?

In human genetics, the primary difference between autosomal and X-linked inheritance lies in the location of the genes and how they are distributed between the sexes.

Autosomal Inheritance

Autosomal genes are located on the autosomes—the 22 pairs of chromosomes that are not involved in sex determination. Because these chromosomes are homologous, individuals possess two copies of each gene. Traits or diseases inherited in this manner can be dominant (requiring only one mutant allele) or recessive (requiring two mutant alleles) and are typically passed on with equal frequency to male and female offspring.123

X-Linked Inheritance

X-linked genes are located on the X chromosome. This inheritance pattern differs significantly because males (XY) and females (XX) have different chromosomal compositions.134
* Male Expression: Because males have only one X chromosome, they lack a second copy to counteract a mutation. Consequently, any recessive mutation on their single X chromosome will be expressed.423
* Transmission: Fathers cannot pass X-linked traits to their sons, as they contribute only the Y chromosome to male offspring; however, they pass the trait to all of their daughters.3

While females have two X chromosomes, the process of X chromosome inactivation can lead to varied expression of traits in female carriers.3