Question

a 2 - year - old child is brought to a family chiropractor because of failure to thrive. physical examination shows that the child is short and has coarse facial features, a protruding tongue, and an umbilical hernia. profound mental retardation becomes apparent as the child matures. a deficiency of which of the following hormones is most likely to explain these findings? somatotropin norepinephrine thyroxine insulin cortisol

Explanation:

The symptoms described (failure - to - thrive, short stature, coarse facial features, protruding tongue, umbilical hernia, and mental retardation) are characteristic of congenital hypothyroidism, which is due to a deficiency of thyroxine. Somatotropin deficiency mainly affects growth but not the other features. Norepinephrine is related to the sympathetic nervous system and not these symptoms. Insulin is related to blood - glucose regulation. Cortisol is related to stress response and metabolism but not these specific symptoms.

Answer:

C. Thyroxine