Early Diagnosis of 46,XX Testicular Difference of Sexual Development: Unusual Presentation with Increased Nuchal Translucency.

INTRODUCTION: 46,XX testicular disorder of sexual development (DSD) may present prenatally as a mismatch between phenotype and karyotype. Enlarged nuchal translucency is an abnormal sign of many disorders. We present a first trimester fetus with increased nuchal translucency that was later determined to be a 46,XX testicular DSD. CASE PRESENTATION: A first-trimester pregnancy ultrasound revealed enlarged nuchal translucency. Chorionic villous sampling documented a 46,XX karyotype. Subsequent ultrasounds identified male external genitalia. FISH analysis documented a SRY gene translocation. At birth, the infant had normal male internal and external genitalia. CONCLUSIONS: 46,XX testicular DSD may present in the first trimester with an enlarged nuchal translucency.