Altered infant feeding patterns in boys with acquired nonsyndromic cryptorchidism.

BACKGROUND: Genetic and environmental factors likely influence susceptibility to nonsyndromic cryptorchidism, a common disease presenting at birth or in later childhood. We compared cases and controls to define differential risk factors for congenital versus acquired cryptorchidism. METHODS: We compared questionnaire and clinical data from cases of congenital cryptorchidism (n = 230), acquired cryptorchidism (n = 182) and hernia/hydrocele (n = 104) with a group of healthy male controls (n = 358). Potential predictor variables (p < 0.2 in univariable analysis) were included in stepwise multivariable logistic regression models. RESULTS: Temporary (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.4-0.8) or exclusive (OR, 0.6; 95% CI, 0.4-0.9) breastfeeding was reduced and soy formula feeding increased (OR, 1.8; 95% CI, 1.2-2.9) in acquired but not congenital or hernia/hydrocele groups. The highest risk estimates were observed for primary soy formula feeding with limited or no breastfeeding (OR 2.5; 95% CI, 1.4-4.3; adjusted OR, 2.7; 95% CI, 1.4-5.4) in the acquired group. Primary feeding risk estimates were equivalent or strengthened when multivariable models were limited to age greater than 2 years, full-term or not small for gestational age, or Caucasian subjects. Pregnancy complications and increased maternal exposure to cosmetic or household chemicals were not consistently associated with either form of cryptorchidism in these models. CONCLUSIONS: Our data support reduced breastfeeding and soy formula feeding as potential risk factors for acquired cryptorchidism. Although additional studies are needed, hormonally active components of breast milk and soy formula could influence the establishment of normal testis position in the first months of life, leading to apparent ascent of testes in childhood. Birth Defects Research (Part A), 2012.

Insulin-like factor 3 levels in amniotic fluid of human male fetuses.

BACKGROUND: Rodent studies suggest that the peptide hormone insulin-like factor 3 (Insl3) made by the fetal testis is responsible for the first transabdominal phase of testicular descent, and may be affected by xenobiotics to disrupt male reproductive tract development. To date, there is very little information on the production of INSL3 by the human fetus during gestation. The objective of the present study was to determine the concentrations and time course during pregnancy of INSL3 and testosterone production in human fetuses and their associations with maternal characteristics, pregnancy complications and outcome. METHODS: This is a retrospective cohort study in which women who contributed amniotic fluid specimens to a bank from 2003-2006 were followed to determine their pregnancy complications and pregnancy outcome. Amniotic fluid specimens were collected from the Reproductive Genetics Laboratory of the Hospital of the University of Pennsylvania subsequent to routine amniocentesis. INSL3 and total testosterone levels were measured in amniotic fluid (from n = 50 female, n = 237 male fetuses) by validated immunoassays and correlated with maternal characteristics, pregnancy complications and outcomes. RESULTS: INSL3 was only detectable in amniotic fluid from male fetuses, and highest levels occurred from weeks 15-17 of gestation. INSL3 concentration was positively associated with increased birth weight, the occurrence of pre-eclampsia and advanced maternal age, but not with testosterone levels. CONCLUSIONS: INSL3 concentration in human amniotic fluid is potentially predictive of fetal sex and pre-eclampsia, and presumably reflects the functioning of the fetal Leydig cell population.

Analysis of five single nucleotide polymorphisms in the ESR1 gene in cryptorchidism.

BACKGROUND: Recent findings suggest that a specific haplotype, including five single nucleotide polymorphisms (SNPs) in the 3'-terminal region of the estrogen receptor alpha gene (ESR1), is associated with the risk for cryptorchidism, but results have been conflicting in different populations. The goal of this study was to further define the association between this specific ESR1 haplotype and the risk for nonsyndromic cryptorchidism in a multiracial American population including Caucasian, African American, and Asian American subjects. METHODS: Applied Biosystems TaqMan SNP Genotyping Assays were used to identify the genotypes of the five SNPs in ESR1 in 152 nonsyndromic cryptorchidism cases and 160 healthy controls. RESULTS: For the five SNPs, there were no significant differences in genotype frequencies between cases and controls. The four estimated haplotypes at the 3' region of ESR1 gene were also not associated with the occurrence of cryptorchidism, but the haplotype AGATC was associated with the severity of cryptorchidism. SNP12 (rs6932902) in ESR1 was not associated with cryptorchidism per se, but was associated with increasing severity of cryptorchidism. Severe cases were more likely to have GG genotype (93%) than moderate (54%) cases (p = .04), and this association was in recessive mode (p = .02). The allele distribution of this SNP was also significantly different between moderate and severe cases: 97% of severe cases had the G allele while only 76% of moderate cases had the G allele (p = .03). CONCLUSIONS: SNP12 in ESR1 is not associated with the occurrence of cryptorchidism but is associated with the severity of cryptorchidism.

Second trimester amniotic fluid bisphenol A concentration is associated with decreased birth weight in term infants.

Bisphenol A (BPA) is an endocrine disrupting chemical with ubiquitous environmental exposure. Animal studies have demonstrated that in utero BPA exposure leads to increased adult body weight. Our aim was to characterize human fetal BPA exposure by measuring BPA concentration in second trimester amniotic fluid (AF) samples and to study its relationship with birth weight (BW) in full term infants. To achieve these goals, we developed a total BPA assay utilizing derivatization with pentafluorobenzyl followed by analysis with LC-ECAPCI-MS/MS with a limit of detection of 0.08ng/mL and limit of quantification (LOQ) of 0.25ng/mL. The mean BW of infants with AF BPA 0.40-2.0ng/mL was 241.8g less than infants with AF BPA less than the LOQ after controlling for covariates (p=0.049). No effect was seen outside this range indicating a non-monotonic effect. Our data suggest that low level BPA exposure in utero decreases BW and needs further study.

Allelic variants in HOX genes in cryptorchidism.

BACKGROUND: Cryptorchidism is one of the most common congenital anomalies and is associated with increased risk for infertility and testicular cancer later in life. Findings from animal models and small clinical studies suggest that the posterior HOX genes (paralogs 9-13) could be potential candidate genes for cryptorchidism and that the HOX genes are functionally redundant within paralogous groups. METHODS: The coding regions and exon-intron boundaries of the 16 posterior HOX genes were sequenced and analyzed in group 1 (44 nonsyndromic cryptorchidism cases and 46 healthy controls). Those specific variants found to be significantly different between cases and controls in group 1 were examined in DNA from group 2 (108 cases and 114 controls). RESULTS: A total of 57 variants was found in group 1, among which the allele frequency of 180A>G (A60A) in HOXD13 alone was significantly elevated in cases versus controls (P = 0.02). In the combined 1 + 2 group, cases were also more likely than controls to have the G allele (P = 0.002). As predicted by an exonic splicing enhancer finder program, the 180A>G (A60A) variant is expected to have an influence on the splicing of transcripts from HOXD13. In group 1, case subjects were more likely to carry multiple variants in HOXA13 and HOXD13 (P = 0.02) than controls. CONCLUSIONS: The variant 180A>G (A60A) in HOXD13 is a risk factor for cryptorchidism, and a dynamic equilibrium of genes in HOX paralog 13 is involved in the pathogenesis of cryptorchidism.

Evaluation of potential modifiers of the palatal phenotype in the 22q11.2 deletion syndrome.

OBJECTIVE: To evaluate potential modifiers of the palatal phenotype in individuals with the 22q11.2 deletion syndrome. DESIGN: Data from 356 subjects enrolled in a study of the 22q11.2 deletion syndrome were used to evaluate potential modifiers of the palatal phenotype. Specifically, subjects with and without velopharyngeal inadequacy and/or structural malformations of the palate were compared with respect to gender, race, and genotype for variants of seven genes that may influence palatal development. METHODS: The chi-square test or Fisher exact test was used to evaluate the association between palatal phenotype and each potential modifier. Odds ratios and their associated 95% confidence intervals were used to measure the magnitude of the association between palatal phenotype, subject gender and race, and each of the bi-allelic variants. RESULTS: The palatal phenotype observed in individuals with the 22q11.2 deletion syndrome was significantly associated with both gender and race. In addition, there was tentative evidence that the palatal phenotype may be influenced by variation within the gene that encodes methionine synthase. CONCLUSIONS: Variation in the palatal phenotype observed between individuals with the 22q11.2 deletion syndrome may be related to personal characteristics such as gender and race as well as variation within genes that reside outside of the 22q11.2 region.

Molecular epidemiology of hypospadias: review of genetic and environmental risk factors.

Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. It is characterized by altered development of the urethra, foreskin, and ventral surface of the penis. In this review, the embryology, epidemiology, risk factors, genetic predisposition, and likely candidate genes for hypospadias are described. Recent reports have identified increases in the birth prevalence of mild and severe forms of hypospadias in the United States from the 1960s to the present. Studies in consanguineous families and small case series have identified allelic variants in genes controlling androgen action and metabolism that cause hypospadias, but the relevance of these findings to the general population is unknown. Concern has also focused on whether exposure to endocrine disrupting chemicals (EDC) with antiandrogenic activity is the cause of this increase. Hypospadias is believed to have a multifactorial etiology in which allelic variants in genes controlling androgen action and metabolism predispose individuals to develop this condition. When genetic susceptibility is combined with exposure to antiandrogenic agents, a threshold is surpassed, resulting in the manifestation of this birth defect. A clear role for exposure to antiandrogenic environmental chemicals has yet to be established in the etiology of hypospadias, although results from laboratory animal models indicate that a number of environmental chemicals could be implicated. Molecular epidemiology studies that simultaneously examine the roles of allelic variants in genes controlling androgen action and metabolism, and environmental exposures are needed to elucidate the risk factors for these anomalies and the causes of the increased rate of hypospadias.

Reproductive hormone levels in infants with cryptorchidism during postnatal activation of the pituitary-testicular axis.

PURPOSE: Testosterone and luteinizing hormone secretion is reportedly impaired in infants born with cryptorchidism. To better characterize this phenomenon, we studied a range of hormones that normally increase in boys during the first few months of life. MATERIALS AND METHODS: A case-control study was conducted of boys with nonsyndromic cryptorchidism identified at birth (cases) and boys with descended testes presenting to the urology clinic without endocrine related concerns (controls). Blood was obtained at approximately 2 months of age and up to 3 urine samples were obtained at monthly intervals until age 120 days. Testosterone, estradiol, luteinizing hormone and follicle-stimulating hormone were measured in plasma and urine, and inhibin B, sex hormone-binding globulin (SHBG) and leptin were measured in plasma using standard assays. Data were analyzed using t tests with and without log transformation. RESULTS: Of 20 cases 15 were unilaterally cryptorchid. Although 7 testes descended spontaneously, 2 became cryptorchid again during followup and, therefore, 15 boys required orchiopexy. Diagnoses of 26 controls included foreskin problems (15), prenatal hydronephrosis (4), penile torsion (2), ectopic kidney (1) and hydrocele (1). None of the plasma or urinary hormone measurements was significantly different between boys requiring orchiopexy and controls. Plasma SHBG and testosterone, SHBG, estradiol and leptin, and body mass index positively correlated, while testosterone and body mass index negatively correlated. CONCLUSIONS: We failed to identify any significant differences in hormone levels between controls and boys with cryptorchidism during activation of the pituitary-testicular axis in early infancy. These data suggest that impairment of this process may be uncommon in boys with nonsyndromic cryptorchidism.