Presently transgenic models are available for all the given diseases, except:

Options

A. Cystic fibrosis
B. Rhecumatoid arthritis
C. Carddiomyopathy
D. Alzheimer s disease

Answer

To determine which disease does not have a transgenic model available, we can analyze each option provided in the question. Here's a step-by-step solution:

### Step 1: Understand Transgenic Models
Transgenic models are organisms (often mice) that have had their DNA manipulated to express or suppress specific genes. These models are crucial for studying the genetic basis of diseases and testing potential treatments.

**Hint:** Recall that transgenic models are primarily used to study the genetic contributions to diseases.

### Step 2: Evaluate Each Disease
We need to evaluate the diseases listed in the options to see which one lacks a transgenic model.

- **Option A: Cystic Fibrosis**
- There are established transgenic models for cystic fibrosis, which help researchers understand the disease and test treatments.

**Hint:** Think about common genetic diseases that have been extensively studied.

- **Option B: Rheumatoid Arthritis**
- Transgenic models exist for rheumatoid arthritis, allowing for the exploration of its genetic factors and potential therapies.

**Hint:** Consider autoimmune diseases and their research models.

- **Option C: Cardiomyopathy**
- Currently, there are no widely accepted transgenic models specifically for cardiomyopathy. This condition is complex and not as well represented in transgenic studies compared to the other diseases listed.

**Hint:** Reflect on heart diseases and their representation in genetic studies.

- **Option D: Alzheimer’s Disease**
- Transgenic models for Alzheimer’s disease are available and are used to study the progression and potential treatments for this neurodegenerative condition.

**Hint:** Alzheimer's is a major area of research, especially in genetics.

### Step 3: Conclusion
After evaluating all the options, we find that the disease for which transgenic models are not available is **Cardiomyopathy** (Option C).

**Final Answer:** C. Cardiomyopathy