Supplementary Material for: A Genetics Study in the Foreskin of Boys with Hypospadias

<b><i>Introduction:</i></b> Hypospadias is a malformation of the genitourinary system in males, characterized by the placement of the urethral opening in the ventral surface of the penis. Although controversies continue about etiology, endocrine disrupting chemicals that disrupt normal endocrine signaling at the receptor or signal transduction level are thought to play an essential role in etiology. This study aimed to investigate the receptor gene expressions of the sex hormones and <i>FGFR2</i>, <i>HOXA13</i>, and <i>TGFB1</i>, which are considered to play an essential role in developing hypospadias. <b><i>Methods:</i></b> The samples from the foreskin of 26 patients with hypospadias and 26 healthy children who underwent circumcision operations were collected. <i>ESR1</i>, <i>AR</i>, <i>FGFR2</i>, <i>HOXA13</i>, and <i>TGFB</i> gene expressions were investigated by real-time PCR in samples obtained during surgery. <b><i>Results:</i></b> In the hypospadias group, <i>ESR1</i> expression was increased (<i>p</i> = 0.013), and <i>AR</i> and <i>FGFR2</i> expressions were decreased, which were found to be statistically significant (<i>p</i> = 0.027 and <i>p</i> = 0.003, respectively). There was no statistically significant difference between hypospadias and control groups in <i>TGFB</i>and <i>HOXA13</i>expression levels (<i>p</i> &gt; 0.05). <b><i>Discussion:</i></b> The results suggest that sex hormone receptors and FGFR2 may play an essential role in developing male external genital structures at the gene level. The defects in the expression of these genes can contribute to understanding the development of hypospadias.

**引言：** 尿道下裂（hypospadias）是男性泌尿生殖系统的先天畸形，以尿道外口开口于阴茎腹侧为典型特征。尽管其病因学尚存争议，但可在受体或信号转导层面干扰正常内分泌信号的内分泌干扰化学物，被认为在其发病机制中发挥关键作用。本研究旨在探究性激素受体基因，以及被证实与尿道下裂发生发展密切相关的*FGFR2*、*HOXA13*与*TGFB1*基因的表达水平。

**方法：** 本研究采集26例尿道下裂患者的包皮组织样本，以及26例行包皮环切术的健康儿童的包皮组织样本。通过实时荧光定量PCR（real-time PCR）检测手术采集样本中*ESR1*、*AR*、*FGFR2*、*HOXA13*及*TGFB*基因的表达水平。

**结果：** 尿道下裂组中，*ESR1*的表达水平显著升高（*p*=0.013），*AR*与*FGFR2*的表达水平则显著降低，差异均具有统计学意义（*p*分别为0.027与0.003）。*TGFB*与*HOXA13*的表达水平在尿道下裂组与对照组间无统计学差异（*p*>0.05）。

**讨论：** 本研究结果提示，性激素受体与FGFR2可能在基因层面参与男性外生殖器结构的发育调控。上述基因的表达异常，可为阐释尿道下裂的发生发展机制提供参考依据。