The Second-to-Fourth Digit Ratio in Cryptorchidism: A Case-Control Study

Area of Science:

• Pediatric endocrinology
• Developmental biology
• Genetics

Background:

• Homeobox (Hox) genes influence limb and genital development, impacting digit ratio and fetal androgen production.
• The second-to-fourth digit ratio (2D:4D) is a potential marker for prenatal androgen exposure.
• Testicular descent in boys is influenced by fetal testicular androgen levels.

Purpose of the Study:

• To investigate if the digit ratio can serve as an indicator for disease status in children.
• To assess differences in digit ratio among infants with cryptorchidism, hydrocele, and healthy controls.

Main Methods:

• A prospective study enrolled 196 children aged 6-23 months.
• Participants included groups with cryptorchidism (46), hydrocele (50), healthy boys (50), and healthy girls (50).
• The second and fourth finger lengths were measured by two investigators to determine the 2D:4D ratio.

Main Results:

• The mean 2D:4D ratios for the left and right hands showed no significant differences across the cryptorchidism, hydrocele, healthy boy, and healthy girl groups.
• No significant relationship was found between 2D:4D ratios and age, weight, or height in any group.
• The digit ratio did not vary significantly among the studied pediatric groups.

Conclusions:

• The second-to-fourth digit ratio (2D:4D) did not significantly differ in infant boys with cryptorchidism compared to those with hydrocele or healthy controls.
• The digit ratio failed to reflect disease conditions in the infant period.
• 2D:4D ratio is not a reliable indicator of cryptorchidism or hydrocele in infants.