Restriction digests of the clone give the following sizes (kb): EcoRI/HindIII--2.8, 2.2, 1.0. An EcoRI/HindIII double digest shows insert fragment sizes of 2.2 and 1.0 kb. The MspI RFLP shows significant linkage to autosomal recessive vitamin D dependency type I (thetam = 0.018, Z = 3.2). D12S17 and D12S25 detect the same polymorphism and therefore represent the same locus. Codominant segregation of the MspI polymorphism has been demonstrated in 42 3-generation families. Also detects a 2-allele RsaI RFLP (3.0, 1.7 kb) not tested in pedigree studies. Enzyme(s) not detecting polymorphism: BamHI, BglII, EcoRI, HindIII, PstI, PvuII, TaqI. |