A 9-year-old girl is brought to a new pediatrician by her mother over concerns regarding her weight. She has a history of developmental delay, and her mother mentions that she is noticeably shorter than her peers. She is noted to have a round face and bilaterally shortened fourth metacarpals on examination. She is in the 96th percentile for weight and below the 3rd percentile for height for her age. Laboratory testing reveals hypocalcemia. Which additional laboratory findings are associated with this patient’s most likely diagnosis?