A Case of Disorder of Sex Development in Red Deer (Cervus elaphus)

Disorders of sex development (DSDs) are rare in free-ranging cervids and remain poorly documented.

We describe a hunted red deer (Cervus elaphus) with well-developed antlers and male-typical morphology but female-like external genitalia, characterized by a hypertrophic clitoris/penile-like protrusion and absence of a scrotum. External genital tissues were available for histopathology, which revealed penile-type structures, including cavernous tissue and urethral-like epithelium. Genetic sex was assessed using PCR amplification of SRY and ZFX/ZFY markers from formalin-fixed, paraffin-embedded (FFPE) material. Due to the degraded DNA, we redesigned ZFY primers to yield a short amplicon suitable for compromised templates. PCR positivity for SRY and ZFY indicated the presence of Y-linked sequences. However, in the absence of internal reproductive organs, karyotyping and hormonal analyses, the etiology and DSD category cannot be determined, and chromosomal mosaicism or other Y-chromosome anomalies cannot be excluded.

This report documents an unusual phenotype in a free-ranging red deer and provides a practical short amplicon ZFY assay for sex marker detection in degraded samples. Both genetic and environmental causes of DSD were considered; however, no definitive etiology could be established.