A case of disorder of sex development in red deer (Cervus elaphus elaphus)

We describe a hunted red deer (Cervus elaphus 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. Only 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 positive 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.