A region of the mouse genome homologous to human chromosome 1q21 affects facial clefting.

We sought to determine whether mouse chromosomal regions homologous to human chromosomal regions implicated in the etiology of facial clefting would be related to the incidence of spontaneous cleft palate (CP) or cleft lip with or without cleft palate [CL(P)], Dilantin-induced CL(P), hydrocortisone-induced CP, and/or 6-aminonicotinamide-induced CP. We found that a region on mouse chromosome 3, homologous to human chromosome 1q21, significantly increased the incidence of sporadic CL(P) when the allele from the A/J inbred strain was present. None of the other chromosomal regions or conditions studied had significant associations with this susceptibility to facial clefting, although there was a suggestion that the B allele of the same region was associated with hydrocortisone-induced CP. Thus, the region on human chromosome 1q21 should be further studied for a role in the etiology of human CL(P).