An Infant With <i>DHX37</i> Variant: A Novel Etiology of 46,XY DSD and Literature Review

46,XY sex reversal 11 (SRXY11) is a rare and recently identified form of 46,XY difference in sexual development (DSD), caused by variants in the DEAH-Box Helicase 37 gene (<i>DHX37</i>). <i>DHX37</i> is crucial for ribosome biogenesis, but its specific role in gonadal development remains unclear. The genital phenotype varies widely, ranging from typical female to typical male. We present a 46,XY infant with prenatal ultrasound findings of atypical genitalia. Amniotic fluid gene analysis revealed a known heterozygous pathogenic variant in <i>DHX37</i>, p.R308Q (c.923G>A), confirmed postnatally. The patient was born with markedly undervirilized genitalia with posteriorly fused labioscrotal folds, a single introitus, no clitoromegaly, and nonpalpable gonads. Laboratory evaluation at multiple points showed undetectable anti-Müllerian hormone (AMH) and inhibin B levels, elevated gonadotropin levels, and negligible testosterone levels. Clinical course was complicated by urine retention in the vagina and uterus and hydronephrosis requiring catheterization. Endoscopy revealed a urogenital sinus with separate urethral and vaginal openings and 2 cervices leading into 2 separate uteri suggestive of a bicornuate bicollis uterus. Laparoscopy revealed 2 intra-abdominal gonads adjacent to the fallopian tubes. Evidence for inheritance, penetrance, genotype-phenotype correlation, and risk of malignancy in SRXY11 is limited to case reports.