A child with stunted growth with a stuffed-belly, and short stature with mental retardation is suffering from the deficiency of which of the following:

Thyroxine Increases Metabolism of Cells. Thyroxine indirectly affects protein metabolism by increasing metabolism of the cells. If insufficient carbohydrates and fats are available for energy, thyroxine causes rapid degradation of proteins and uses them for energy. Conversely, if adequate quantities of carbohydrates and fats are available and excess amino acids are also available in the extracellular fluid, thyroxine can actually increase the rate of protein synthe­sis. In growing animals or human beings, deficiency of thyroxine causes growth to be greatly inhibited because of lack of protein synthesis. In essence, it is believed that thyroxine  has little specific effect on protein metabolism but does have an important general effect by increasing the rates of both normal anabolic and normal catabolic protein reactions. Thyroid hormones stimulate metabolic rate, calorigenesis, cardiac function, and normal mentation, and interact synergistically with catecholamines. Thyroid hormones also play critical roles in development, particularly of the nervous system, and growth. Note: Lack of adequate amount of thyroxine can result in stunted growth with a stuffed-belly, and short stature with mental retardation. Reference: GUYTON AND HALL TEXTBOOK OF MEDICAL PHYSIOLOGY, THIRTEENTH EDITION(INTERNATIONAL EDITION ) page no 1014