Step 1: Understand the Pedigree Chart

The pedigree chart shows inheritance of a disease across generations. We observe that affected individuals (filled symbols) appear in every generation, and both males and females are affected.

Step 2: Check for Autosomal vs. Sex-Linked Inheritance

Since both males and females are affected, the disease is not Y-linked (only males would be affected) and likely not X-linked dominant (which would show no male-to-male transmission). Here, there is male-to-male transmission (e.g., affected father passing to son), which rules out X-linked inheritance. Thus, the disease is autosomal.

Step 3: Check for Dominant vs. Recessive Inheritance

Affected individuals appear in every generation, and every affected child has at least one affected parent. This pattern is characteristic of an autosomal dominant disorder. In autosomal recessive disorders, affected individuals may not appear in every generation, and affected children can have unaffected parents.

Final Answer

The disease is Autosomal dominant.

Related Topics and Formulae

Types of Inheritance Patterns

• Autosomal Dominant: Affected individuals in every generation; affected child has at least one affected parent.
• Autosomal Recessive: Skips generations; affected child can have unaffected parents (carriers).
• X-linked Dominant: Affects females more; no male-to-male transmission.
• X-linked Recessive: Affects males more; affected males pass trait to all daughters (carriers).
• Y-linked: Only males affected; passed from father to all sons.

Key Formulae (Probability in Pedigree Analysis)

For autosomal dominant inheritance, if one parent is heterozygous affected (Aa) and the other is unaffected (aa), the probability of an affected child is:

For autosomal recessive inheritance, if both parents are carriers (Aa), the probability of an affected child (aa) is: