may be present in patients with PHP-Ib, but it may be too mild to become clinically manifest. This is similar to the TSH resistance in PHP-Ib, which can be absent in many PHP-Ib patients, is milder than in PHP-Ia, and can be accounted for by the partial imprinting of Gsα in the thyroid [151]. Mild short-stature has been recently reported in some patients who show PTH-resistance and GNAS imprinting defects [152], consistent with GHRH resistance and resultant growth hormone deficiency. Nevertheless, it remains unknown whether patients with PHP-Ib have reduced Gsα expression in the pituitary and whether they display GHRH resistance.
