Mendelian Puzzles

摘要

Mendelian genetic disorders, rare clinical phenotypes arising from a single-gene mutation, are extremely diverse traits that affect every organ system, age group, and human popu lation (7). Their cumulative incidence is rare (under 5%) because the clinical phenotypes are deleterious and affected individuals rarely reproduce. They persist in the population by de novo mutation in the past few generations, but some recessive mutations are an excep tion because their effects can be sheltered in carriers for hundreds of generations.