Non-specific Inclusion Criteria :

• Parents of legal age having signed a free and informed consent for the participation of their child
• Biological mother of a boy aged between 1 and 6 months
• Biological mother with a minimum hair length of 18 cm
• Biological mother who has signed a free and informed consent for her participation
• Biological mother and child affiliated with or beneficiaries of a national health insurance plan
• Biological mother who is fluent in written and spoken French

Specific Inclusion Criteria for Case Group:

- The child has an isolated anterior or middle hypospadias, without any other complex variations of genital development (borderline penile size, unilateral or bilateral cryptorchidism, retractile testes), without malformation syndrome and without identified genetic etiology

Specific Inclusion Criteria for Control Group:

- The child must not present any complex variations in genital development (hypospadias, borderline penis size, unilateral or bilateral cryptorchidism, retractile testes)

Exclusion Criteria:

• Child with another congenital anomaly or malformative syndrome
• Child with an endocrine pathology
• Biological mother or child under legal protection, guardianship, or curatorship
• Biological mother or child in the exclusion period of a previous study
• Biological mother or child included in another clinical study involving a drug

Specific Exclusion Criteria for Case Group:

Biological mother/child pairs if a genetic variant explaining hypospadias is found during genetic analysis.