Direct estimation of the recombination frequency between the RB1 gene and two closely linked microsatellites using sperm typing

In this study, single sperm typing has been used for high-resolution recomb ination analysis between the retinoblastoma gene and two closely linked ext ragenic microsatellites (D13S284 and D13S1307), The analysis of 1198 single sperm from three donors allowed the determination of recombination fractio ns between RB1.20 and D13S284 and RB1.20 and D13S1307 of 0.022 and 0.033, r espectively. These results show that RB1 gene and the two microsatellites a re closely linked, which validates their potential use in indirect genetic diagnosis of retinoblastoma.