In rats treated with estradiol, iodine deficiency has been shown to lead to changes similar to benign breast changes that are reversible by increased iodine in the diet. In a few studies, iodine supplementation had beneficial effects (such as reducing the presence of breast cyst, fibrous tissue plaques and breast pain) in women with fibrocystic breast changes.Protective effects of iodine on breast cancer have been postulated from epidemiologic evidence and described in animal models. In view of the antiproliferative properties of iodine in breast tissue, molecular iodine supplementation has been suggested as an adjuvant in breast cancer therapy. Risk factors
Following is a list of potential risk factors that may lead to iodine deficiency:
Low dietary iodine
Selenium deficiency
Pregnancy
Exposure to radiation
Increased intake/plasma levels of goitrogens, such as calcium
Sex (higher occurrence in women)
Smoking tobacco
Alcohol (reduced prevalence in users)
Oral contraceptives (reduced prevalence in users)
Perchlorates
Thiocyanates
Age (for different types of iodine deficiency at different ages)

Pathophysiology
Iodine accounts for 65% of the molecular weight of T4 and 59% of T3. There is a total of 15–20 mg of iodine in the human body, primarily concentrated in thyroid tissue and hormones. Thirty percent of iodine is distributed in other tissues, including the mammary glands, eyes, gastric mucosa, choroid plexus, arterial walls, the cervix, and salivary glands. In the cells of these tissues, iodide enters directly by sodium-iodide symporter (NIS). Venturi S, Guidi A, Venturi M (1996). "[Extrathyroid iodine deficiency disorders: what is the real iodine requirement?]"". Le Basi Razionali della Terapia. 16: 267–275. Pellerin P (1961). "La tecnique dautoradiographie anatomique a la temperature de lazote liquide".
Epidemiology
Ring chromosome 14 syndrome is extremely rare, the true rate of occurrence is unknown (as it is less than 1 per 1,000,000), but there are at least 50 documented cases in the literature. See also
Ring chromosome 18 syndrome
Ring chromosome 20 syndrome

References
Further reading
Disorders, National Organization for Rare (2003-01-01). NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. ISBN 9780781730631. Zollino M.; Seminara L.; Orteschi D.; Gobbi G.; Giovannini S.; Della Giustina E.; Frattini D.; Scarano A.; Neri G. (2009). "The Ring14 Syndrome: Clinical and Molecular Definition" (PDF). American Journal of Medical Genetics. 149A (6): 1116–1124. doi:10.1002/ajmg.a.32831. PMID 19441122. S2CID 22919033. == External links ==