HB Muskegon [β83(EF7)GLY→ARG]: A New Variant Found in a Family from the US

Hb Muskegon was detected during a routine hematologic evaluation. It was found initially in a 1-year-old boy and his father. The hematologic data for these individuals appeared normal: for the father - Hb 15.4 g/dl, PCV 0.45 l/l, RBC 5.29 x 10 super(12)/l, MCV 85 fl, MCH 29.1 pg, and MCHC 34.1 g/dl. The heat and isopropanol tests for unstable Hb were negative, and the percentage of Hb F was 0.7%. Hb A sub(2) was 3.0% as measured by the microchromatographic method. Cellulose acetate electrophoresis at pH 8.6 revealed an abnormal band slightly anodic to Hb S, on citrate agar (pH 6.2) the abnormal band migrated between Hbs S and C. Globin chain electrophoresis in alkaline and acid buffers produced a band in the beta super(s) position. Screening of other family members showed that the paternal grandmother and an uncle also have the variant. The grandfather was normal.