The genomic region at 15q11.2q13 represents a hotspot for copy-number variations (CNVs) due to nonallelic homologous recombination. Previous studies have suggested that the development of 15q11.2q13 deletions in sperm may be affected by seasonal factors because patients with Prader-Willi syndrome resulting from 15q11.2q13 deletions on paternally derived chromosomes showed autumn-dominant birth seasonality. The present study aimed to determine the frequency of 15q11.2q13 CNVs in sperm of healthy men and clarify the effects of various environmental factors, i.e., age, smoking status, alcohol intake, and season, on the frequency. Thirty volunteers were asked to provide semen samples and clinical information once in each season of a year. The rates of 15q11.2q13 CNVs were examined using 2-color FISH. The results were statistically analyzed using a generalized estimating equation with negative binomial distribution and a log link function. Consequently, informative data were obtained from 83 samples of 26 individuals. The rates of deletions and duplications ranged from 0.04 to 0.48% and from 0.08 to 0.30%, respectively. The rates were not correlated with the age, smoking status, or alcohol intake. Sperm produced in winter showed 1.2 to 1.4-fold high rates for both deletions and duplications as compared with sperm produced in the other seasons; however, there was no significant difference. These results demonstrate high and variable CNV rates at 15q11.2q13 in sperm of healthy men. These CNVs appear to occur independent of the age, smoking status, or alcohol intake, while the effect of season remains inconclusive. Our results merit further validation.

中文翻译：

---

健康男性精子 15q11.2q13 常见拷贝数变异的频率

由于非等位基因同源重组，15q11.2q13 的基因组区域代表了拷贝数变异 (CNV) 的热点。先前的研究表明，精子中 15q11.2q13 缺失的发展可能受到季节性因素的影响，因为父源染色体上 15q11.2q13 缺失导致的 Prader-Willi 综合征患者表现出以秋季为主的出生季节性。本研究旨在确定健康男性精子中 15q11.2q13 CNV 的频率，并阐明各种环境因素，即年龄、吸烟状况、酒精摄入量和季节对频率的影响。要求 30 名志愿者在一年中的每个季节提供一次精液样本和临床信息。使用 2 色 FISH 检查 15q11.2q13 CNV 的发生率。使用具有负二项式分布和对数链接函数的广义估计方程对结果进行统计分析。因此，从 26 个人的 83 个样本中获得了信息数据。缺失率和重复率分别为 0.04 至 0.48% 和 0.08 至 0.30%。这些比率与年龄、吸烟状况或酒精摄入量无关。与其他季节产生的精子相比，冬季产生的精子的缺失和重复率高 1.2 至 1.4 倍；然而，没有显着差异。这些结果表明健康男性精子中 15q11.2q13 的 CNV 率高且可变。这些 CNV 的发生似乎与年龄、吸烟状况或饮酒量无关，而季节的影响尚无定论。