using System;

​

public class Program

{

    public static void Main()

    {

        var baseInstance = new Base()

        {

            Name = "Base Instance", 

        };

        var child = (Child)baseInstance;

    }

}

​

public class Base

{

    public String Name

    {

        get;

        set;

    }

}

​

public class Child : Base

{

    public String Description

    {

        get;

        set;

    }

}