I'm confused by your comments. So the "4th quad" looks exactly like the other 3, but he's not one of the sibliings?
Like I explained above,
multiples can look very different. So one cannot guess who those multiples are by simply using the look. The news report may be correct or it may not. They might have made a mistake and claimed an unrelated person as one of the siblings. or the 4th one is one of the siblings, as they mentioned in the news. We simply cannot tell from the look. Please allow me to say it one more time, genetically speaking, multiples CAN look very different if they originate from multiple fertilized eggs. this is possible because a female CAN release more than one egg when ovulating. One good exmaple is having twins of different sex (the so-called dragon-phoenix twins). The fact that one of the twins is male and the other is female is clear evidence that the twins don't share the same genetic information, hence they WILL look different. Of course the same thing can also happen even when both of the tiwns have the same sex. Since both eggs are fertilized independent of each other and by different sperms, the probability of both twins sharing the same genetic info is excatly the same as two brothers or two sisters in the normal sense. This possibility of having multiple fertilized eggs, hence different-looking twins/multiples is increased by orders of magnitude when the person has fertility treatments.
