Abstract
BACKGROUND: Pericentric inversion of Chromosome 9 is a common chromosomal abnormality, occasionally linked to clinical conditions such as ambiguous genitalia, warranting its inclusion in differential diagnoses. Sexual ambiguity is a tragic and highly distressing condition that imposes deep emotional and spiritual concerns on the family. Therefore, it is essential to adopt a rational and immediate approach, including clinical, hormonal, genetic, molecular, and radiographic investigations, to determine its cause and guide the therapeutic strategy. CASE PRESENTATION: A 35-year-old gravida 1 Iranian woman at 37 weeks of pregnancy delivered a 1900-g newborn via cesarean section due to intrauterine growth restriction. The newborn exhibited ambiguous genitalia, including severe hypospadias and a micropenis. Karyotyping revealed a normal chromosomal count with a pericentric inversion of Chromosome 9 (46XY, inv (9) (p12q13)). Hormonal and ultrasound evaluations were normal, and no family history of sexual development disorders was noted. CONCLUSION: Pericentric inversion of Chromosome 9 can result in ambiguous genitalia, emphasizing the importance of karyotyping in the diagnostic evaluation for proper management and counseling.