Kazakh — Mongol Kinship Terms Similarities

So I've noticed about similarities between Kinship Terms among Mongolian and Kazakh. I wonder is it coincidence? Quite an interesting topic.

Khalkh Mongolian — Kazakh Нагац — Нағашы (Naγaču in Middle and Classical Mongolian, Nagaču in Inner Mongolian: Chakhar, Ordos, Khorchin). Here ғ=γ) Авсан — Абысын Ажин — Ажын Төрхөм — Төркін Худ — Құда (Худа in Buryat. Here қ=q) Худгуй — Құдағи (Худагы in Buryat) Бөл — Бөле Баж — Бажа Зээ — Жиен Зээнцэр — Жиеншар

I wonder it's just common Altaic terms or direct ancient loanwords?