Several other factors that have been associated with linear enamel hypoplasia include infections (such as measles, otitis, respiratory infections, rubella, syphilis, tetanus, urinary tract infections, and varicella), metabolic disorders (such as asthma, diabetes, and diseases of the following glands: adrenal, parathyroid, pituitary, and thyroid), mineral deficiencies (such as calcium, fluorine, magnesium, and phosphorus), protein deficiencies (such as amelogenin, enamelin, and tuftelin), and vitamin deficiencies (such as vitamins A, C, D, and K) [13-17]. Here, ENAM is linked to respiratory tract infectious disorder.