Genetic inheritance : Basic patterns overview

Genetic conditions are often passed down from parents to their children through a process known as inheritance. The pattern of inheritance depends on the location and behaviour of the faulty gene causing the condition. There are several patterns of inheritance, including autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and mitochondrial inheritance. Each pattern has specific characteristics that determine the risk of transmitting the condition to the next generation and whether one or both parents must carry the gene for a child to be affected.

Autosomal dominant conditions require only one copy of a faulty gene for the disease to manifest, meaning if one parent has the condition, there is a 50% chance it will be passed to each child. Autosomal recessive conditions, on the other hand, occur only when an individual inherits two copies of a faulty gene, one from each carrier parent, making the likelihood of expression less frequent in each generation. X-linked dominant and recessive conditions are associated with genes on the X chromosome, with dominant conditions requiring only one copy of the faulty gene in females and recessive conditions predominantly affecting males, who have only one X chromosome. Lastly, mitochondrial inheritance involves genes in the mitochondria,...