Which of the following genetic principles best explains the findings in this family? A 6-year old boy is found to have almond-shaped eyes, temperature instability, mental retardation, hyperphagia, and obesity. Cytogenetic analysis shows a balanced translocation involving chromosome 15q11-q13. His father and paternal aunt are found to have an identical balanced translocation. His aunt’s 5-year old daughter has a history of inappropriate laughter, abnormal gait, and mental retardation.
A. Anticipation B. Genetic drift C. Heteroplasmy D. Imprinting E. Pseudodominant inheritance