DNA sequence derived from a heteroduplex fragment.

A heteroduplex band from patient no. 34 was isolated, reamplified, and sequenced. Note unambiguous sequence up to the arrowed nucleotide (T at nt 775 on the PIG-A cDNA sequence), then ambiguous sequence. By subtracting the normal sequence 775-GTCAGCAGACTTGTT from the observed sequence the alternative peaks can be clearly read as 778-AGCAGACTTGTTAC showing deletion of 3 nucleotides.