[Intersexuality in horses].
Intersexuality is a rare congenital anomaly of horses. Diagnosis of intersexuality is difficult because there are usually no specific changes in the reproductive tract visible. During a period of five years, ten patients with reduced fertility or suspected intersexuality respectively were investigated using cytogenetic, molecular genetic, histopathological and endocrinological methods. In one case a 64,XX/63,X0 mosaicism was found. In six cases male pseudohermaphroditism was verified. These patients showed a male karyotype, testes and rudimentary parts of a female reproductive tract were present. One horse was suspected to be a male pseudohermaphrodite but the gonads were not examined. One horse was suspected to be affected by an XX-sex several syndrome and in one case a SRY-negative XY-sex reversal syndrome was most likely. In the case of an XX-sex reversal syndrome, there is a female chromosomal constitution, an uterus and cranial parts of the vagina are present but also testes tissue and possibly an enlarged penis like clitoris. Here an XX-sex reversal syndrome was suspected but not confirmed as it was not possible to examine the gonads and verify tissue from testes. Therefore a pseudohermaphroditismus femininus could not be excluded. In cases of XY-sex reversal syndrome the patients show a male chromosomal constitution, parts of a female reproductive tract but no testes tissue is present. For the horse described here, a deletion of the SRY gene was the most likely cause for the XY-sex reversal syndrome.
Kuiper
H
H
Institut für Tierzucht und Vererbungsforschung, Stiftung Tierärztliche Hochschule Hannover. heidi.kuiper@tiho-hannover.de
Distl
O
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D000818:Animals; D012734:Disorders of Sex Development / Q000175:diagnosis / Q000235:genetics / Q000662:veterinary*; D005260:Female; D005835:Genitalia / Q000002:abnormalities*; D005838:Genotype; D006734:Horse Diseases / Q000175:diagnosis / Q000235:genetics*; D006736:Horses; D007246:Infertility / Q000209:etiology / Q000662:veterinary; D008297:Male; D009030:Mosaicism / Q000662:veterinary; D010641:Phenotype; D012733:Sex Differentiation