Observed and expected frequencies of structural hemoglobin variants in newborn screening surveys in Africa and the Middle East: deviations from Hardy-Weinberg equilibrium.
Observed and expected frequencies of structural hemoglobin variants in newborn screening surveys in Africa and the Middle East: deviations from Hardy-Weinberg equilibrium.
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DOI：
10.1038/gim.2015.143
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发表时间：
2016-03
期刊：
影响因子：
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通讯作者：
Grosse SD
中科院分区：
文献类型：
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作者：
Piel FB;Adamkiewicz TV;Amendah D;Williams TN;Gupta S;Grosse SD
我们的目的是比较观察到的和预期的基因型比例从新生儿筛查调查结构血红蛋白变异。我们对非洲和中东新生儿血红蛋白S和C筛查调查进行了系统回顾。我们将观察到的频率与假设Hardy-Weinberg平衡（HWE）的预期频率进行了比较。通过精确检验识别显著偏离。计算固定指数FIS以评估过度纯合性。我们比较了新生儿估计校正和未校正的HWE偏差使用人口统计数据。60个样本报告了非洲和中东血红蛋白变异的基因型计数。观察到的和预期的计数在27%中匹配。在42个样本中观察到的镰状细胞性贫血（SCA）个体数高于预期，在24个样本中达到显著性（p<0.05）。高FIS在整个研究区域都很常见。根据FIS校正的SCA新生儿估计总数为33，261年出生，而不是撒哈拉以南非洲38个样本的24，958年出生，中东12个样本的1，109年出生，而不是578年出生。观察到的和预期的基因型频率之间的差异是常见的研究地区的血红蛋白变异的调查。需要进一步研究，以确定和量化造成这种偏差的因素。根据卫生和保健工作评估得出的估计数可能大大低估了每年受严重急性呼吸道综合症影响的新生儿人数（撒哈拉以南非洲高达三分之一，中东为一半）。
Our objective was to compare observed and expected genotype proportions from newborn screening surveys of structural hemoglobin variants. We conducted a systematic review of newborn screening surveys of hemoglobins S and C in Africa and the Middle-East. We compared observed frequencies to those expected assuming Hardy-Weinberg equilibrium (HWE). Significant deviations were identified by an exact test. The fixation index FIS was calculated to assess excess homozygosity. We compared newborn estimates corrected and uncorrected for HWE deviations using demographic data. Sixty samples reported genotype counts for hemoglobin variants in Africa and the Middle-East. Observed and expected counts matched in 27%. The observed number of sickle-cell anemia (SCA) individuals was higher than expected in 42 samples, reaching significance (p<0.05) in 24. High FIS were common across the study regions. The estimated total number of newborns with SCA, corrected based on FIS, were 33,261 annual births instead of 24,958 for the 38 samples across sub-Saharan Africa and 1,109 annual births instead of 578 for 12 samples from the Middle East. Differences between observed and expected genotype frequencies are common in surveys of hemoglobin variants in the study regions. Further research is required to identify and quantify factors responsible for such deviations. Estimates based on HWE might substantially underestimate the annual number of SCA affected newborns (up to one third in sub-Saharan Africa and one half in the Middle East).