Jankiel was born in 1843. Jankiel's father was Srul Yosel LERER and his mother was Malka REYCH. His paternal grandparents were Jankiel LERER and Necha SZPIRER; his maternal grandparents were Nusym REYCH and Zlota. He had a sister named Devorah. He was the older of the two children. He had a half-brother and two half-sisters, named Shlomo, Golda and Chana. He died at the age of 1 in 1844.