Genetics: Inheritance Patterns and Pedigree Analysis

Flashcards covering key Mendelian inheritance patterns and terminology used in pedigree analysis from the lecture notes.

Autosomal Recessive Trait

An inheritance pattern that appears equally in both sexes, often skips generations (affected individuals can be born to unaffected parents), and appears more frequently in children of consanguineous marriages.

Autosomal Dominant Trait

An inheritance pattern that appears equally in both sexes, does not skip generations (affected offspring must have an affected parent unless a new mutation), and both sexes can transmit the trait to their offspring.

X-linked Recessive Trait

An inheritance pattern where more males than females are typically affected, affected sons can be born to unaffected mothers (skips generations), it is never passed from father to son, and all daughters of affected fathers are carriers.

X-linked Dominant Trait

An inheritance pattern where both males and females are usually affected (often more females than males), it does not skip generations, affected sons must have an affected mother, and affected fathers pass the trait on to all of their daughters.

Y-linked Trait

An inheritance pattern where only males are affected, it is passed from father to all sons, and does not skip generations.

Pedigree

A diagram that illustrates the relationship of individuals in a family, their sex, and the transmission of a genetic trait over several generations.

Pedigree Generations

Indicated by Roman numerals in a pedigree diagram.

Individuals in a Pedigree

Members of a generation in a pedigree indicated by Arabic numbers.

Female in Pedigree

Represented by circles in a pedigree diagram.

Male in Pedigree

Represented by squares in a pedigree diagram.

Affected Individual in Pedigree

Represented by shaded (black) symbols in a pedigree diagram.

Skipping Generations (in pedigree)

When an affected offspring is born to parents who are not affected; a characteristic often seen in recessive traits like X-linked recessive.