Holoprosencephaly in a long‐tailed macaque (Macaca fascicularis): A case report

Abstract

A long-tailed macaque fetus with ethmocephaly, alobar holoprosencephaly, and arhinia is reported. This fetus was exposed to an antiprogestational agent, RU 486 (2.5 mg/kg intramuscular, once daily), during gestational days 15-18. Three hypotheses are proposed to explain these malformations: (1) they are a direct result of drug exposure, (2) they are a secondary effect of treatment and the result of decreased blood supply to the developing embryo due to an incomplete abortion, and (3) they represent a spontaneous occurrence.

Frequency of spontaneous congenital defects in rhesus and cynomolgus macaques

“…Another objective of updating our malformation data is to aid in the evaluation of spurious malformations in teratology (safety assessment) studies at the CRPRC. Occasionally, single defects have been observed in teratology studies carried out at the CRPRC [19,6,7,18,27,29,28]. Owing to the isolated nature of the malformation, and the lack of dose relationship or a biologically plausible mechanism for teratogenicity, these cases have all been attributed to a spontaneous or unknown cause rather than related to drug treatment.…”

C-1073 (Mifepristone) in the Adjunctive Treatment of Alzheimers Disease

“…In a study of monkey embryos exposed to mifepristone, no adverse effects were noted [42]. Birth defects were noted in one long-tailed macaque exposed to mifepristone, but it was not known if these malformations were due to mifepristone exposure or were of spontaneous occurrence [43].…”

Semilobar Holoprosencephaly Associated with Multiple Malformations in a Foal

“…The holoprosencephaly syndrome has been reported in lambs (Roth et al., ; Zeiss et al., ), pigs (Holmes et al., ; Fisher et al., ), dogs (Sullivan et al., ; Martínez et al., ) and macaques (Siebert et al., ; Tarantal et al., ). Single cases have been documented in a calf (Cho et al., ) and a horse (Koch et al., ).…”