Analysis of IVS 11 mutations in whole blood DNA.

(A) Sequence of segment g.31689-31704 (IVS 11) in PCR fragment g.31016-31920 (IVS 10-exon 12) from normal control, Sib A, Sib B, and their mother, as indicated. Arrows indicate g.31701. Sib A is homozygous, and her mother is heterozygous, for g.31701T>A. Blood DNA of Sib B gives a “double ladder.” (B) Ethidium bromide–stained agarose gel of a DdeI digest of fragment g.31016-31920 (IVS 10-exon 12) amplified from normal control DNA (lane 1), and from blood DNA of Sib A (lane 2), Sib B (lane 3), and their parents (lane 4, father; lane 5, mother). The 234- and 85-nt products are due to a novelDdeI site introduced by the g.31701T>A mutation.