Which of the following is not a example of recessive autosomal disease ?

Options

A. Haemophilia
B. Cystic fibrosis
C. Pheylketonuria
D. Sickle-cell anaemia

Explanation

To determine which of the following diseases is not an example of a recessive autosomal disease, we will analyze each option provided in the question: hemophilia, cystic fibrosis, phenylketonuria, and sickle cell anemia.

### Step-by-Step Solution:

1. **Identify the diseases:**
- The diseases listed are:
- Hemophilia
- Cystic fibrosis
- Phenylketonuria
- Sickle cell anemia

2. **Analyze Hemophilia:**
- Hemophilia is a genetic disorder characterized by the inability of blood to clot properly.
- It is known to be a **sex-linked recessive disorder**, specifically linked to the X chromosome.
- Therefore, it is **not an autosomal recessive disease**.

3. **Analyze Cystic Fibrosis:**
- Cystic fibrosis is a genetic disorder that primarily affects the lungs and pancreas, leading to severe respiratory and digestive problems.
- It is caused by mutations in the CFTR gene and is classified as an **autosomal recessive disorder**.

4. **Analyze Phenylketonuria (PKU):**
- Phenylketonuria is a metabolic disorder caused by the deficiency of the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine.
- This condition is also classified as an **autosomal recessive disorder**.

5. **Analyze Sickle Cell Anemia:**
- Sickle cell anemia is a hereditary condition where red blood cells become misshapen (sickle-shaped) and can lead to various health complications.
- It is classified as an **autosomal recessive disorder**.

6. **Conclusion:**
- Among the options, hemophilia is the only disease that is not an example of a recessive autosomal disease. The other three diseases (cystic fibrosis, phenylketonuria, and sickle cell anemia) are all autosomal recessive disorders.

### Final Answer:
The correct answer is **hemophilia** (Option A), as it is a sex-linked recessive disorder, not an autosomal recessive disorder.

---