Looking to update a column with data from other existing columns in the same table.

Example of my current data:

```
ID            DOB     FirstName     LastName    Gender
1x2v3b4n5m  19560809    John          Doe         M

```

What I'm looking to do is Replace the ID = DOB, first 3 char FirstName, first 3 char LastName, and Gender

```
ID
19560809JOHDOEM

```

Thanks in advance, this is stumping me.