Craniofacial morphology comparison between TcMAC21 and TcHSA21 rat models of Down syndrome: An interspecies analysis

This study quantitatively compares craniofacial skeletal features in two transchromosomic rodent models of Down syndrome—TcMAC21 mice and TcHSA21 rats—using micro-computed tomography and geometric morphometrics. Both models display characteristic Down syndrome craniofacial features including increased neurocranial roundness and facial retraction, with the rat model showing a more pronounced brachycephalic phenotype, while integration patterns between cranial components remain evolutionarily conserved.