<qa>  What is a condition that causes a permanent loss in height?Thyroid hormone is necessary for normal growth. Treatment with thyroxine thyroid hormone results in rapid catch-up growth, which mostly happens during the first 18 months. Growth is accompanied by increased bone age, which means early fusion closure of the growing bones of the bones and reduced growth potential. For example, a patient, who is 10 years old but has bone age of 12 years, has growth potential of a 12 year old and will stop growing 2 years earlier than a 10 year old patient. According to the literature, prolonged juvenile hypothyroidism low thyroid condition resulted in a permanent loss in height and only 70 catch-up growth was generally achieved with thyroxine replacement. 