Isolated Thyroid-Stimulating Hormone Deficiency, also known as isolated thyrotropin deficiency, is related to hypothyroidism, congenital, nongoitrous, 4 and hypothyroidism, congenital, nongoitrous, 1. An important gene associated with Isolated Thyroid-Stimulating Hormone Deficiency is TSHB (Thyroid Stimulating Hormone Subunit Beta). Affiliated tissues include thyroid and pituitary, and related phenotypes are thyroid hypoplasia and pituitary hypothyroidism