Biparental inheritance of chromosomal abnormalities in male twins with non-syndromic mental retardation
In a monozygotic twin couple with mental retardation (MR), we identified a maternally inherited inversion and a paternally inherited translocation: 46,XY,inv(10)(p11.2q21.2)mat,t(9;18)(p22;q21.1) pat. The maternally inherited inv(10) was a benign variant without any apparent phenotypical implications. The translocation breakpoint at 9p was within a cluster of interferon a genes and the 18q21 break