Transmission ratio distortion at the INS-IGF2 VNTR

Eaves, IAB, S. T.; Forster, P.; Ferber, K. M.; Ehrmann, D.; Wilson, A. J.; Bhattacharyya, S.; Ziegler, A. G.; Brinkmann, B.; Todd, J. A.,  Nature Genetics,  22:324-325. 1999.

Transmission ratio distortion (TRD) is defined as a statistically significant departure from mendelian transmission. So far, evidence of this in humans has been limited or controversial1,2,3,4, and the few established examples involve chromosome rearrangements in lower organisms5.; ; The variable number of tandem repeat (VNTR) polymorphism 596 bp 5´ of the insulin gene (INS) regulates expression of both INS and the gene encoding insulin-like growth factor 2 (IGF2). The VNTR can be subdivided into two main allele sizes, class I and class III, in Europeans. Class III alleles are associated with reduced expression of INS and IGF2 in the pancreas and placenta6. As lower expression of VNTR class III-associated INS/IGF2 alleles early in fetal development may reduce the chances of survival in utero, the locus is considered a candidate for exhibiting TRD.