若 PKU 发病率 q² = 1/10000 = 0.0001,则 q = 0.01、p = 0.99。携带者频率 2pq = 2×0.99×0.01 = 0.0198(约 1/50)。这是医学遗传学中 HWE 的经典应用。{"result":"q=0.01, p=0.99: AA=0.9801, Aa=0.0198, aa=0.0001.","metadata":{"input":{"mode":"frequency","q":0.01},"result":{"p":0.99,"q":0.01,"AA":0.9801,"Aa":0.0198,"aa":0.0001,"carrierRate":0.0198}}}
卡方检验:100 个体(49 AA, 42 Aa, 9 aa) 100 个个体:p = (2×49+42)/200 = 0.70,q = 0.30。预期:AA = 49、Aa = 42、aa = 9。χ² = 0.00,不显著——群体符合 HWE。(这些频率下预期计数恰好等于观测值。){"result":"N=100: p=0.7, q=0.3. Expected AA=49, Aa=42, aa=9. χ²=0.0000 (df=1, not significant).","metadata":{"input":{"mode":"counts","AA":49,"Aa":42,"aa":9},"result":{"p":0.7,"q":0.3,"expAA":49,"expAa":42,"expaa":9,"chiSquare":0,"significant":false}}}