Which inheritance type is NOT one of the listed types of inheritance for human diseases?

• A. Autosomal Dominant
• B. Incompletely dominant
• C. X-linked dominant
• D. Y-linked

Answer: (B)

In the context of genetic inheritance patterns described for human diseases, the correct answer is the option that mentions incompletely dominant inheritance.

Autosomal dominant inheritance is a well-established pattern where only one copy of a mutated gene (from one parent) can cause the disease. This type of inheritance is seen in conditions like Huntington's disease.

X-linked dominant inheritance refers to conditions caused by mutations on the X chromosome, where typically, one mutated copy can lead to the disease in both males and females, though its effects can vary. An example is Rett syndrome.

Y-linked inheritance concerns genes located on the Y chromosome, which are passed from father to son. Conditions related to Y-linked inheritance are less common but are recognized, such as some forms of male infertility.

Incompletely dominant inheritance is actually not a recognized classification within human genetic diseases. Incomplete dominance typically refers to situations in plants or some animal traits where the phenotype of heterozygous individuals is intermediate between those of the two homozygotes, rather than a clear categorization of human disease inheritance. Thus, it does not fit within the broader context of human disease inheritance types.