Autosomal Recessive Inheritance

• Characteristics of autosomal recessive inheritance:

– no difference in expression between males and females

– matings between affected individuals produce 100% affected offspring

– Affected genotype (filled in shape) must be “dd”

– Unaffected genotypes (empty shapes) can be either “DD” or “Dd”

Autosomal Recessive Inheritance

• Characteristics of autosomal recessive inheritance:

– no difference in expression between males and females

– matings between affected individuals produce 100% affected offspring

– Affected genotype (filled in shape) must be “dd”

– Unaffected genotypes (empty shapes) can be either “DD” or “Dd”

Must be “dd”

Must be “Dd”

For the rest of the people you cannot be sure if they are “DD” or “Dd”.

Autosomal Dominant Inheritance

• Characteristics of autosomal dominant inheritance:

– no difference in expression between males and females

– no unaffected heterozygous individuals– does not skip generations– Affected genotypes (filled in shapes) can be

either “Dd” or “DD”– Unaffected genotype (empty shape) must be “dd”

Autosomal Dominant Inheritance

• Characteristics of autosomal dominant inheritance:

– no difference in expression between males and females

– no unaffected heterozygous individuals– does not skip generations– Affected genotypes (filled in shapes) can be either “Dd” or “DD”– Unaffected genotype (empty shape) must be “dd”

Must be “Dd”All empty shapes must be “dd”

Must be “Dd”

Sex-linked (X-linked) recessive inheritance

• Characteristics of sex-linked (X-linked) recessive inheritance:

– most affected individuals will be male

– affected females must have an affected father and either a heterozygous or affected mother

– affected females will have 100% affected sons

– tends to skip generations– Affected genotypes (filled in

shapes) must be “XdXd ” or

“XdY”– Unaffected genotypes

(empty shapes) can be “XDXD ”, “XDXd ”, or “XDY”

Sex-linked (X-linked) recessive inheritance

• Characteristics of sex-linked (X-linked) recessive inheritance:

– most affected individuals will be male

– affected females must have an affected father and either a heterozygous or affected mother

– affected females will have 100% affected sons

– tends to skip generations– Affected genotypes (filled in

shapes) must be “XdXd ” or

“XdY”– Unaffected genotypes

(empty shapes) can be “XDXD ”, “XDXd ”, or “XDY”

XDY

XdY

XdY

XDXd

XDXd

XD_

XDY

XD_XD_

• Characteristics of sex-linked (X-linked) dominant inheritance:

– affected males must have affected mothers

– affected females must have one affected parent

– affected males will have 100% affected daughters

– affected females are expected to produce half normal, half affected offspring

– Affected genotypes (filled in shapes) can be “XDXD ”, “XDXd ”, or “XDY”

– Unaffected genotypes (empty shapes) must be “XdXd ” or “XdY”

Sex-linked (X-linked) Dominant Inheritance

• Characteristics of sex-linked (X-linked) dominant inheritance:

– affected males must have affected mothers

– affected females must have one affected parent

– affected males will have 100% affected daughters

– affected females are expected to produce half normal, half affected offspring

– Affected genotypes (filled in shapes) can be “XDXD ”, “XDXd ”, or “XDY”

– Unaffected genotypes (empty shapes) must be “XdXd ” or “XdY”

Sex-linked (X-linked) Dominant Inheritance

XdXd XDY

XdY

XdXd

XDXdXDXd

XDYXDXd