HELP me with this Q-NBME 5-4-11 - mpowerag

[ArchivalUser]

In a 2day old full term healthy baby, screening tests show DECREASED serum T4 and NORMAL serum TSH. test on venous blood confirm this findings. The venous free T4 is NORMAL. which of the following is the most likely explanaition.

a. dysgenesis of the thyroid gland
b. hypopituatarism
c. inborn error of thyroxine synthesis
d. iodine deficiency
e. thyroxine binding globulin deficieny

why is venous T4 normal but serum T4 decreased ?????

NO CLUE...however i have eliminated a few. lets see what u guys think.

[ArchivalUser]

E. thyroxine binding globulin deficieny.

TSH normal- No hypopituitarism.

Total T4 decreased with normal free T4- thyroxine binding globulin deficieny

Total T4 decreased with decrease in free T4- other options.

[ArchivalUser]

ee

[ArchivalUser]

E E E