I see, and keep silent

respice

Consider the end.

Due to the nature of his parents marriage, Regulus Black was born with hemophilia. His parents were both second-cousins. In the Black family itself, it was extremely common for one to have it.

Even in the pureblood society as whole, it was not an uncommon thing. The purebloods wanted to keep their blood pure, which ultimately lead to inbreeding.

Hemophilia itself is a disorder in which blood does not clot normally. Which causes excessive bleeding (externally or internally) after an injury or damage.

Similar to the european royal families, the genes for hemophilia would pass through the Black family.

The inbreeding had caused the gene pool to increased the chances of the disorder being passed to their children or their children being carriers of it themselves.

As a toddler, he would spend a lot of time in St. Mungo's to be treated for it.

As a result of his disorder, his parents were protective of him. When he was a child, he was only allowed to play inside. He was quite clumsy as a child, walking or crashing into things accidentally.

Even as a teenage, it took a lot of persuasion (and some arguing) on his part to be allowed to play for the quidditch team.

There was one instance during quidditch when he fell off his broom. He only fracture his arm but there was lots and lots of bleeding in the healing process.

His parents were quite insistent on not letting him play quidditch again. Regulus, not wanting to lose one of the only things making himself happy, had to practically begged them to be allowed to play again, promising to be more careful when playing.

While Sirius distanced himself from the Black family, he couldn't help but be worried and look out for his baby brother sometimes.

Orion, in particular was quite set on not letting Regulus join the death eaters. But the pressure from Walburga and several other Black family members made him relent and eventually let Regulus to join.