A Novel β-Globin Chain Hemoglobin Variant, Hb Allentown [β137(H15)Val→Trp (GTG>TGG) HBB: c.412_413delinsTG, p.Val138Trp], Associated with Low Oxygen Saturation, Intermittent Aplastic Crises and Splenomegaly
Hemoglobin (Hb) variants may be associated with low oxygen saturation and exacerbated episodes of anemia from common stressors such as viral infections. These attributes frequently cause increased clinical concern and unnecessary and expensive testing if not considered earlyin the evaluation of the patient. Some clinically significant Hb variants result in a normal Hb electrophoresis result, which can be method-dependent. Herein we describe a patient with low oxygen saturation and a history of hemolytic anemia who was subsequently found to carry a novel, unstable b-globin variant that we have named Hb Allentown [b137(H15)Val!Trp (GTG4TGG) HBB: c.412_413delinsTG, p.Val138Trp] for the place of identification of the variant.
Hb Allentown is formed by a rare double nucleotide substitution within the same codon. Additionally, positive identification of rare Hb variants characterized by a single method is discouraged, as the Hb variant was misclassified as Hb S-South End or b6(A3)Glu!Val;b132(H10)Lys!Asn (HBB: c.[20A4T;399A4C]) by the initial laboratory
Published In/Presented At
Collier, AB., Coon, LM, Monteleone, P, Umaru, S, Swanson, KC, Hoyer, JD, Oliveria, JL. (December 16, 2015). A Novel β-Globin Chain Hemoglobin Variant, Hb Allentown [β137(H15)Val→Trp (GTG>TGG) HBB: c.412_413delinsTG, p.Val138Trp], Associated with Low Oxygen Saturation, Intermittent Aplastic Crises and Splenomegaly, Hemoglobin.
Medicine and Health Sciences | Pediatrics
Hematology-Medical Oncology Division, Hematology-Medical Oncology Division Fellows and Residents, Department of Pediatrics, Department of Pediatrics Faculty, Department of Pediatrics Residents