OMIA:000393-9615 : Tetragametic chimerism (including Freemartin) in Canis lupus familiaris

In other species: cattle , deer , pig , sheep , bighorn sheep , water buffalo , horse

Categories: Reproductive system phene

Links to MONDO diseases: No links.

Mendelian trait/disorder: no

Considered a defect: yes

Key variant known: no

Cross-species summary: Tetragametic chimerism is a rare, sex chromosome disorder of sex development characterized by the two different haploid sets of maternal and paternal chromosomes and variable phenotype - from normal male or female genitalia, to different degrees of ambiguous genitalia, and often infertility. Also, in the cases of monochorionic dizygotic twins, it can be confined to blood of both twins. [ Orphanet : 199310 ] Freemartin or free-martin is an infertile female animal which is the twin of a male animal whose anti-Müllerian hormones affected its development in utero. Genetically the animals are chimeric (microchimerism, XX/XY leukocyte chimerism) - some stem cells from the male twin are received during in utero development via vascular connections between placentas. The condition is mostly reported in ruminants due to their multicotyledonary placenta type. Phene was renamed to 'Tetragametic chimerism' [16/11/2022]

Breed: French Bulldog.


2020 Szczerbal, I., Nowacka-Woszuk, J., Nizanski, W., Dzimira, S., Ligocka, Z., Jastrzebska, A., Kabala, B., Biernacik, M., Przadka, P., Switonski, M. :
Disorders of Sex Development Are an Emerging Problem in French Bulldogs: A Description of Six New Cases and a Review of the Literature. Sex Dev :, 2020. Pubmed reference: 32203972 . DOI: 10.1159/000506582.

Edit History

  • Created by Frank Nicholas on 25 Mar 2020