Hereditary
hemoglobin H (HbH) disease was diagnosed in 2 Japanese sisters who presented with aplastic crisis following acute human parvovirus B19 (HPV B19)
infection. The proband, an 8-year-old girl, developed persistent
fever and pallor, and samples of her peripheral blood showed
hypochromic microcytic anemia. Other laboratory data were consistent with
hemolytic anemia.
Fever and signs of
hypochromic microcytic anemia also developed in her sister 9 days later.
Cation exchange HPLC analysis of their
hemoglobin revealed abnormal
hemoglobin migrating faster than HbF, a finding consistent with HbH. Although they presented neither
arthralgia nor
skin rash, we concluded that their aplastic crisis was induced by HPV B19, because HPV B19
DNA was detected in samples of their peripheral blood by PCR analysis, and HPV B19
IgM and
IgG antibody titers were elevated. A genetic analysis of the
alpha-globin gene in both sisters and their parents disclosed that the father was heterozygous for alpha-Thal-2, the mother, heterozygous for alpha-Thal-1, and the proband and her sister, double heterozygous for alpha-Thal-1 and alpha-Thal-2. alpha-Thal-2 is a 3.7 kb-deletion allele.