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.