Age of the mother as a risk factor and timing of hypospadias repair according to severity

Severity-Dependent Profile of the Metabolome in Hypospadias

Background & Objective: Hypospadias, characterized by the displacement of the opening of the urethra at any point in the medial-ventral side of the penis, is classified upon severity as mild (Type I) and severe (Type II and Type III) hypospadias. Hypospadias' etiology is idiopathic in the majority of cases, and underlying causes seem of multifactorial origin. Studies regarding genetic variants support this notion. It is unknown whether downstream gene products fit this profile. This study evaluated the metabolome of hypospadias by using the emerging technology of metabolomics in the search for distinct cellular processes associated with hypospadias' etiology according to the severity of this congenital urogenital condition. Methods: Foreskin samples were collected during urethroplasty from boys with Type I, II, and III hypospadias or undergoing elective circumcision (N = 28) between 5 and 28 months of age. Samples were processed and submitted to gas chromatography-mass spectrometry (GC/MS). MetaboloAnalyst (http://www.metaboanalyst.ca/) online platform was used for bioinformatic analyses. Results: Thirty-five metabolites across experimental groups were identified by GC/MS. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) showed that the metabolome of Type II and Type III hypospadias patients differs from the metabolome of Type I hypospadias and control patients. Of those 35, 10 amino acids were found in significantly low concentrations in severe hypospadias: aspartate, glutamate, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, and tyrosine. A high concentration of the amino acid lysine was detected in mild hypospadias. Conclusions: The observed downregulation of specific amino acids in severe hypospadias provides alternative routes for future research aiming to identify disrupted networks and pathways while considering the severity of hypospadias.

A risk prediction model for fetal hypospadias by testing maternal serum AFP and free beta-HCG

OBJECTIVE

We aimed to determine the correlation between serum alpha-fetoprotein (AFP), the free human chorionic gonadotropin beta subunit (free beta-HCG) in pregnant women during the mid-trimester, and fetal hypospadias, and tried to establish a risk prediction model.

METHODS

A multi-center case-control study was conducted. We divided the fetuses into two groups (69 with fetal hypospadias and 62 without fetal hypospadias). Time-resolved immunofluorescence was used to determine the serum levels of AFP and free beta-HCG. The best cut -value and area under curve (AUC) were determined based on the Receiver operating characteristics (ROC) curve, and the diagnostic value of AFP and free beta-HCG was evaluated.

RESULTS

The level of AFP in the study group was 1.14 multiple of Median(MOM), which was higher than in the control group (0.96 MOM); the difference was significant (Z = 2.831, P = .005). Similarly, the free beta-HCG level was 1.30 MOM in the study group, and was also significantly higher than in the control group (0.84 MOM; Z = 3.131, P = .004). We used the AFP and free beta-HCG levels separately to predict fetuses with hypospadias, and the AUCs were 0.644 (95% Confidence interval (CI): 0.5500.737, P = .005) and 0.659 (95% CI: 0.5650.752, P = .002), respectively. According to the ROC curve, the best cut-off values for AFP and free beta-HCG were 0.945 MOM and 1.275 MOM, respectively. When we combined the AFP level with the free beta-HCG level, the AUC was 0.700 (95% CI: 0.610-0.789, P < .001), with a sensitivity of 0.551 and a specificity of 0.855.

CONCLUSION

Combined screening for fetal hypospadias with maternal serum AFP and free beta-HCG levels during the early second trimester has high sensitivity and specificity, which can be used as a new marker.