PAX1 and Klippel-Feil syndrome 1, autosomal dominant: The missense mutations of PAX1 (Pro61Ala; Ala283Pro; Gly289Ser) (Figure 1) could potentially have a pathogenic role, and the question remains whether PAX1 alone, or in conjunction with other genetic or environmental factors, plays a role in the pathogenesis of KFS, need to be confirmed by functional and molecular mechanism studies.