Most relevant clinical and molecular findings in the family studied.

(A) Pedigree of the family studied. Circles denote female family members; squares, male family members; and diamonds, additional members of either sex (the number of additional members is shown in the diamonds). Symbols with diagonal lines indicate deceased members. Filled squares indicate hemizygous males; half-filled circles indicate heterozygous women. (B) Red cell volume histograms obtained with a Bayer Technicon H3 in 3 family members. The vertical tick marks correspond to 10 fL increments. Subject II-7 shows a typical normal picture. Subject II-4 is a typical heterozygous woman with a small proportion of microcytic red cells (tail on the left side of the histogram). The nonanemic hemizygous brother (subject II-3) shows a red cell volume histogram that is almost normal. (C) Dideoxy dye terminator sequence analysis of polymerase chain reaction–amplified, exon 11 genomic DNA from a healthy individual (NL), the proband (II-2), and his brother (II-3). (D) Sequence analysis of reverse transcribedALAS2 mRNA expressed in reticulocytes from the anemic (II-2) and nonanemic (II-3) hemizygous brothers.