(A) Pedigree of the family with congenital HRG deficiency.19 Arrow, the proband; £ {, affected subjects with reduced HRG levels; ⊖, subjects with normal HRG levels; □ ∅︀, deceased family members; □ ○, unexplored subjects. (B) PCR-Taq I digestion analysis of normal and mutated exon 3. Normal exon 3 is composed of 283 bp and is not cleaved by Taq I. Mutated exon 3 with 1 Taq I restriction site (TCGA) is cleaved by the enzyme to form 2 fragments, 162 bp and 121 bp. (C) For each family member, exon 3 amplified by PCR was digested with Taq I and subsequently analyzed by electrophoresis on a 2% agarose gel. Lane 1, molecular weight standard; lanes 2 to 7, Taq I digests of exon 3 derived from the proband and 5 of her family members. {/CAPT;;;left;stack}