16th February 2024

A 32-year-old male presents with two episodes of syncope. ECG reveals a prolonged QTc

A 32-year-old male presents with two episodes of syncope. ECG reveals a prolonged QTc of 550ms. Blood tests showed moderate hypocalcaemia and low PTH levels. Examination revealed the patient had low-set ears, hypertelorism and down-slanting palpebral fissures. She previously had a cleft lip and palate repair as a child. A soft systolic murmur can be heard at the left sternal border.

Which of the following abnormalities can be detected on blood tests?

Select the SINGLE most appropriate option from the list below. Select ONE option only.