- Abetalipoproteinemia is caused by defects of the gene encoding the 97 kDa subunit of a microsomal triglyceride transfer protein. Shoulders, C.C., Brett, D.J., Bayliss, J.D., Narcisi, T.M., Jarmuz, A., Grantham, T.T., Leoni, P.R., Bhattacharya, S., Pease, R.J., Cullen, P.M. Hum. Mol. Genet. (1993)