Cleft Palate Syndrome in the Endangered Spectacled Flying Fox (Pteropus conspicillatus): Implications for Conservation and Comparative Research

Abstract

Cleft palate syndrome, first observed in the spectacled flying fox population in 1998, has produced sporadic neonatal mortality events over the past two decades, with an estimated incidence of up to 1/1000 births per year. This study presents a rudimentary characterisation of the syndrome, presenting gross pathology of syndromic signs upon visual inspection, a histological examination of palate malformations, and syndrome incidence data representing the past two decades. The syndrome presents with a range of signs, primarily congenital palate malformations ranging from a pinhole cleft to a complete hard and soft palate deficit, resulting in the death or abandonment of neonates shortly after birth. The congenital palate malformations are often associated with claw deformities, wiry facial hair, and in some instances, muscle weakness and neurological signs. The natural occurrence of the lethal congenital orofacial birth defects in the spectacled flying fox presents a unique opportunity for the investigation of putative aetiologies, drawing parallels between bat and other mammalian cleft palate risk factors. Further syndrome investigation has the potential to deliver both biodiversity conservation and comparative veterinary and biomedical outcomes.

Exencephaly–Anencephaly Sequence Associated with Maxillary Brachygnathia, Spinal Defects, and Palatoschisis in a Male Domestic Cat

“…Palatoschisis or cleft palate (CP) (OMIA 000197-9685), another malformation identified in our case, is a developmental defect of the palate resulting from a failure of the medial fusion of the palatine processes and manifesting as a separation of the hard or/and soft palate. It has been reported in cattle [27,28], dogs, especially brachycephalic breeds (4), horses [29], cats [30], wild animals (lion, jaguar, tiger) [31,32], and even spectacled flying foxes [33]. Among the human population, palatoschisis with or without cheiloschisis is the most commonly occurring craniofacial birth defect, with a variety of model organisms, such as mice and dogs, utilized to understand the development of orofacial clefts.…”