27457 Al-Sayyid Bedouin Sign Language 100-999 ~3,500 "Al-Sayyid Bedouin Sign Language (ABSL) has arisen in the last 70 years in an isolated endogamous community with a high incidence of nonsyndromic, genetically recessive, profound pre-lingual neurosensory deafness... Within the past three generations, ≈150 individuals with congenital deafness have been born into the community... the deaf members of the community and a significant fraction of its hearing members communicate by means of a sign language. Siblings and children of deaf individuals and other members of a household (which may include a large extended family) often become fluent signers." The emergence of grammar: Systematic structure in a new language On >150 100-999