Mutation of the RHCE gene in DAA and its inheritance in the family. (A) The g nucleotide of the 5′ donor splice-site of intron 4 from the normal RHCE gene in the RhD-negative control is replaced by a t in DAA. The Mse I site created by this mutation is shown. Intronic sequences are in lowercase. (B) Tree of family DAA and Mse I restriction pattern of the genomic PCR product encompassing the exon 4-intron 4 junction are shown. The “silent” RH chromosome segregating in the family is indicated by “- - -”. Solid symbols refer to homozygous (DAA propositus, arrow) or heterozygous individuals for the silent RH gene. Open symbols refer to wild-type RH genes. The 200-bp amplification product is digested with Mse I and is cleaved into two fragments of 148 and 52 bp in the mutated gene. PCR products from RhD-positive (DCe/DCe) and RhD-negative (dce/dce) controls were uncleaved.