- Mapping of human microtubule-associated protein 1B in proximity to the spinal muscular atrophy locus at 5q13. Lien, L.L., Boyce, F.M., Kleyn, P., Brzustowicz, L.M., Menninger, J., Ward, D.C., Gilliam, T.C., Kunkel, L.M. Proc. Natl. Acad. Sci. U.S.A. (1991)