During a medical investigation, an infant was found to possess an extra chromosomes 1. Describe the symptoms the child is likely to develop later in the life.

Explanation

**Step-by-Step Solution:**

1. **Identify the Condition**: The infant has been found to possess an extra chromosome, specifically trisomy of the 21st chromosome, which is commonly known as Down syndrome.

2. **Understand the Symptoms**: Down syndrome is characterized by a range of physical and cognitive symptoms. The child is likely to develop the following symptoms later in life:
- **Mental Retardation**: The child may experience varying degrees of intellectual disability.
- **Physical Features**:
- Round head shape (brachycephaly).
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