Does shmuel off The Boy in the Striped Pyjamas have any brothers or sisters?

In "The Boy in the Striped Pyjamas," Shmuel does not explicitly mention having any brothers or sisters. The story focuses primarily on his friendship with Bruno and the harsh realities of his life in the concentration camp. However, it can be inferred that many families were torn apart during the Holocaust, which adds to the tragic context of Shmuel's character.