IGF1 and cartilage-hair hypoplasia: If CHH is suspected, a full clinical evaluation will be required, including assessment for growth, midline defects, and other pituitary hormone deficiencies (ACTH, thyroid function, insulin-like growth factor-1 (IGF-1), prolactin) (120), as well as MRI of the brain including pituitary and olfactory bulbs (or cranial ultrasound if MRI is not available) and renal ultrasound.