Phenotype‐Genotype Discordance and a Case of a Disorder of Sexual Differentiation

Abstract

Discordance between the genetic sex and phenotype seen on ultrasound can identify disorders of sexual development (DSD) that previously escaped detection until puberty. We describe a 46, XY disorder of sexual differentiation caused by a rare mutation in the SF1 gene (OMIM]184757, (NR5A1). The mutation (NR5A1)‐c.205C > G (p. Arg69Gly) was discovered after a phenotype‐genotype discrepancy was encountered during prenatal care. The baby with 46, XY DSD has female external genitalia but evidence of Y chromosome‐related regression of Müllerian structures and the absence of palpable gonads. We discussed the literature on phenotype‐genotype discrepancy and the importance of care coordination between the antenatal and postnatal teams to ensure a timely diagnosis of DSD.