Speech-language disorder-1 (https://omim.org/entry/602081) is an autosomal dominant disorder characterized by severe orofacial dyspraxia resulting in largely incomprehensible speech. Affected individuals were originally thought to have specific defects in the use of grammatical suffixation rules (Gopnik, 1990Gopnik and Crago, 1991). The phenotype, however, is broader in nature, with virtually every aspect of grammar and language affected (Fisher et al., 1998). Vargha-Khadem et al. (1998) concluded that the disorder is characterized by abnormal development of several brain areas critical for both orofacial movements and sequential articulation, resulting in marked disruption of speech and expressive language.