Two Cases of Cleft Lip and Other Congenital Anomalies in Wild Chimpanzees Living in Kibale National Park, Uganda

Abstract

Cleft lip has been documented in several species of nonhuman primates, but much remains unknown about the occurrence of cleft lip and cleft palate in great apes, probably because such malformations are rare, wild apes are difficult to monitor and observe, and severe cases associated with cleft palates render suckling impossible and lead to early death of infants. The genetic basis of such defects in great apes warrants investigation, as does the possibility that environmental toxins contribute to their etiology in Kibale in ways that could affect humans as well.

Nodular Worm Infections in Wild Non-human Primates and Humans Living in the Sebitoli Area (Kibale National Park, Uganda): Do High Spatial Proximity Favor Zoonotic Transmission?

“…Stress could decrease their immunity level [ 61 , 62 ], and thereby make them more susceptible to parasitic infections. Additionally, about 30% of the chimpanzees have limb deformities caused by poaching, 10% of the individuals suffer from facial dysplasia [ 63 ] and one of them has a cleft lip [ 64 ]. Such mutilations and congenital diseases—suspected to be caused by prenatal exposure to teratogen chemicals—may be associated with other health disorders in the affected individuals and decrease individual’s immunity to pathogens such as parasites [ 65 – 67 ].…”

Patterns of orofacial clefting in the facial morphology of bats: a possible naturally occurring model of cleft palate

“…Although the mouse has proven to be a highly useful experimental model for understanding mammalian craniofacial development, models of orofacial clefting in the mouse generally involve mutations in genes coding for growth factors, receptors, transcription factors, and other molecules with large numbers of pleiotropic effects, the results of which are complex, and often lethal, accompanying abnormalities (Gritli-Linde, 2008). The same appears to be true of the majority of reported instances of orofacial clefting in non-human primates (Kraus & Garrett, 1968;Swindler & Merrill, 1971;Goldschmidt et al 2010;Krief et al 2015). In contrast, clefts in bats occur as a part of normal anatomy and are thus more likely to be determined by subtle changes in the timing and pattern of gene expression than by large-scale mutations radically impacting important genes.…”

“…With such shared, conserved mechanisms of facial ontogeny, it is perhaps not surprising that orofacial clefts similar to those in humans have been described in several mammal species, including domestic dogs (Calnan, 1961;Bleicher et al 1965;Richtsmeier et al 1994;Mart ınez-Sanz et al 2011), cattle (Shupe et al 1968), and primates (Kraus & Garrett, 1968;Swindler & Merrill, 1971;Goldschmidt et al 2010;Krief et al 2015). However, most non-human examples are associated with other congenital cranial malformations and have only rarely been observed in the wild (Krief et al 2015).…”

“…With such shared, conserved mechanisms of facial ontogeny, it is perhaps not surprising that orofacial clefts similar to those in humans have been described in several mammal species, including domestic dogs (Calnan, 1961;Bleicher et al 1965;Richtsmeier et al 1994;Mart ınez-Sanz et al 2011), cattle (Shupe et al 1968), and primates (Kraus & Garrett, 1968;Swindler & Merrill, 1971;Goldschmidt et al 2010;Krief et al 2015). However, most non-human examples are associated with other congenital cranial malformations and have only rarely been observed in the wild (Krief et al 2015). As an experimental model of craniofacial development, the mouse has been extensively studied in relation to induced clefts and has been invaluable in unravelling the molecular mechanisms controlling facial development (Gritli-Linde, 2008, 2012Juriloff & Harris, 2008;Kousa & Schutte, 2016).…”

Facial dysplasia in wild forest olive baboons (Papio anubis) in Sebitoli, Kibale National Park, Uganda: Use of camera traps to detect health defects

“…However, in Sebitoli area in the northern part of Kibale National Park, Uganda, it has been suggested that the malformations observed have different causes. Indeed, exposition to chemicals used on crops, arboricides such as Agent Orange and pollution from combustion exhaust gases from vehicles could be the cause of the high number of congenital malformations observed in the primates including 16 chimpanzees and six baboons ( Papio anubis ) . While chimpanzees are monitored daily in this area, baboons are opportunistically seen and Krief et al .…”