Which of the following disease is an autosomal recessive ?

Options

A. Phenylketonuria
B. Haemophilia
C. Sickle cell anaemia
D. Both (a ) & (c )

Answer

To determine which of the following diseases is autosomal recessive, we need to understand the characteristics of autosomal recessive inheritance and analyze the diseases mentioned.

### Step-by-Step Solution:

1. **Understand Autosomal Recessive Inheritance**:
- Autosomal recessive diseases occur when an individual has two copies of a recessive allele (one from each parent).
- These diseases are not linked to sex chromosomes (X or Y) but are found on the autosomes (non-sex chromosomes).
- A person must inherit two recessive alleles (e.g., "aa") for the disease to manifest; if they have one dominant allele (e.g., "Aa" or "AA"), they will not show symptoms.

2. **Identify the Diseases**:
- The question lists three diseases:
- **Phenylketonuria (PKU)**
- **Hemophilia**
- **Sickle Cell Anemia**

3. **Analyze Each Disease**:
- **Phenylketonuria (PKU)**: This is known to be an autosomal recessive disorder. It occurs due to the accumulation of phenylalanine, which can lead to severe intellectual disability if untreated.
- **Hemophilia**: This is an X-linked recessive disorder, primarily affecting males. It is not autosomal.
- **Sickle Cell Anemia**: This is also an autosomal recessive disorder. It is caused by a mutation in the hemoglobin gene, leading to the distortion of red blood cells.

4. **Conclusion**:
- Both **Phenylketonuria** and **Sickle Cell Anemia** are autosomal recessive diseases.
- **Hemophilia** is not an autosomal recessive disease.

5. **Final Answer**: The diseases that are autosomal recessive are **Phenylketonuria** and **Sickle Cell Anemia**.