Which of the following disordcrs are caused due to recessive autosomal mutations?

Options

A. Turner's syndrome and sickle cell anaemia
B. Edward's syndrome and Down's syndrome
C. cystic fibrosis and phenylketonuria
D. Alzheimer's disease and Huntington's chorea.

Explanation

To determine which disorders are caused by recessive autosomal mutations, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Option A: Turner syndrome and sickle-cell anemia**
- **Turner syndrome**: This condition is caused by the monosomy of the X chromosome (45 chromosomes instead of the normal 46). It is a chromosomal disorder, not caused by a recessive autosomal mutation.
- **Sickle-cell anemia**: This is caused by a mutation in the gene located on chromosome 11 and is classified as an autosomal recessive disorder.
- **Conclusion**: This option is incorrect because Turner syndrome is not a recessive autosomal disorder.

2. **Option B: Edward syndrome and Down syndrome**
- **Edward syndrome**: This is caused by trisomy of chromosome 18 (an extra chromosome), making it a chromosomal disorder.
- **Down syndrome**: This is caused by trisomy of chromosome 21 (also an extra chromosome), which is another chromosomal disorder.
- **Conclusion**: This option is incorrect as both conditions are chromosomal abnormalities, not recessive autosomal mutations.

3. **Option C: Cystic fibrosis and phenylketonuria**
- **Cystic fibrosis**: This disorder is caused by mutations in the CFTR gene located on chromosome 7 and is an autosomal recessive disorder.
- **Phenylketonuria (PKU)**: This condition is caused by a mutation in the PAH gene on chromosome 12 and is also classified as an autosomal recessive disorder.
- **Conclusion**: This option is correct as both cystic fibrosis and phenylketonuria are caused by recessive autosomal mutations.

4. **Option D: Alzheimer's disease and Huntington's chorea**
- **Alzheimer's disease**: This is primarily a neurodegenerative disorder and is not classified as a genetic mutation in a straightforward manner.
- **Huntington's chorea**: This is caused by a mutation in the HTT gene and is classified as an autosomal dominant disorder.
- **Conclusion**: This option is incorrect as neither condition is caused by recessive autosomal mutations.

### Final Answer:
The correct answer is **Option C: Cystic fibrosis and phenylketonuria**, as both are caused by recessive autosomal mutations.