congenital disease; hereditary disease
Refers to a disease or disorder present from birth, whether inherited or caused by prenatal factors. In medical contexts, 先天性疾患 is more precise, but 先天病 is used in general language.
Because of a congenital disease, he had been in and out of the hospital since childhood.
Specifically refers to a hereditary disease passed down through genes, while 先天病 includes both genetic and non-genetic conditions present at birth.
Compound of 先天 (せんてん, 'innate, congenital') and 病 (びょう, 'disease'). The exact historical derivation is uncertain, but the kanji composition transparently reflects the meaning.