Refers to qualities or conditions present from birth, often used in medical or biological contexts (e.g., 先天性疾患).
彼の音楽の才能は先天のものだ。
His musical talent is innate.
先天異常のリスクを調べる検査がある。
There are tests to check the risk of congenital anomalies.
From 先 (before) and 天 (heaven/nature), literally 'before heaven', referring to qualities endowed by nature before birth.