ASPCR analysis showing the mutation at nucleotide −61 in the proband and her parents. PCR fragments spanning nucleotides −416 to +98 were first generated from genomic DNA, and then used as templates in ASPCR. A sense primer with the normal or mutant sequence at its 3′ end was used with a common antisense primer to generate a fragment of 170 bp. Using primers for the normal allele, fragments of the correct size were amplified in both parents, but not in the patient (left). Using primers for the mutant allele, fragments of the correct size were amplified in all family members (right). The result with a normal control (N) are shown in the first lane of each gel. The DNA mol wt markers are a HaeIII digest of φX174.