The incidence of this disorder in North America is 1 in 180.000 normal infants, or approximately 2% of babies with congenital hypothyroidism[15,16]; Prospective studies about thyroid function in neonates born from mothers affected by autoimmune thyroiditis are not available in literature; in particular is not yet known if maternal thyroiditis could influence thyroid hormone levels of the neonate in the first period of life. The gene discussed is TG; the disease is autoimmune thyroid disease.