Afamilial form of hypoparathyroidism is caused by a single point mutation in the gene encoding the preproparathyroid hormone. as a consequence of this point mutation, the signal sequence cannot be cleaved from the prepro-form of the mutant hormone. which statement below best describes the effect of this mutation upon synthesis of the preproparathyroid hormone? a) mrna encoding the mutant preproparathyroid hormone would accumulate in the nucleus and not be transcribed. b) the mutant preproparathyroid protein would not be targeted to the endoplasmic reticulum and thus would be translated by free ribosomes in the cytoplasm. c) the mutant preproparathyroid hormone would be incorrectly folded in the endoplasmic reticulum. d) the mutant preproparathyroid hormone would be inserted into the plasma membrane of the parathyroid cells. e) the mutant preproparathyroid hormone could not be stored in secretory vesicles, but instead would be secreted immediately following synthesis.