Short Answer: there are only 28 clown fish.
The independent factor is typically the unit on the x axis, while the dependent is on the y axis. An Example would be miles per hour, miles would be graphed on the y axis, and hours on the x axis.
The effect of it would be its her brother it runs in her family of the syndrome so of course there would be a most likely chance of her first son getting it because its her first son and the sysndrome is in her brother which is blood and her son which is blood. he may not get the full effect but he would get maybe the whole effect or some of the effect.