Step 1: Treat the disease name as a built-in checklist. Each letter of LEOPARD names one clinical feature, so I can test every option against a letter.
Step 2: Decode the letters: Lentigines, Electrocardiographic conduction defects, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retarded growth, and Deafness.
Step 3: Run the options through this list. Growth retardation lands on R, ECG changes land on E, and hypertelorism lands on O. Each of these is accounted for, so none of them is the exception.
Step 4: The genital feature is abnormal genitalia, which means underdevelopment or hypogonadism. Hypergonadism is the opposite and appears nowhere in the acronym, so it is the odd one out.
\[\boxed{\text{Hypergonadism}}\]