Fitness for Duty: Two Cases of Rare Hemoglobin Variants in U.S. Navy Recruits

Abstract

There are many hemoglobin (Hb) variants that vary in prevalence as well as in clinical significance. Two young male military recruits were incidentally found to have two uncommon Hb variants. This led to an investigation of Hb Lepore-Boston and G-Waimanalo to determine if these U.S. Navy recruits were healthy enough to perform their designated duties. Literature search was conducted using PubMed/Medline. Keywords included "hemoglobinopathy," "hemoglobin variant," "Lepore-Boston," "G-Waimanalo." Results that included cases of Hb Lepore-Boston and G-Waimanalo literature were included. There are few reported cases of these Hb variants that have geographical patterns. It was discovered that Hb Lepore is a group of three variants, characterized by hybrid δβ chains, which expresses features of β-thalassemia trait in heterozygotes. Hb G-Waimanalo or α64(E13) Aspartic acid (Asp) → Asparagine (Asn) is a slow-moving α chain variant, which often results in a mild microcytic hypochromic anemia. Hb Lepore-Boston and G-Waimanalo are benign Hb variants that typically produce mild and asymptomatic anemia. With no clinical relevance in either of these rare Hb variants, the recruits were found qualified for both general duty and their specialty rates.