Hemoglobin Agenogi ‑ A rare abnormal beta globin chain variant.

ABSTRACT

Haemoglobin (Hb) Agenogi is clinically asymptomatic, rare β‑globin chain variant characterized by a substitution of glutamic acid by lysine at position 90 of β‑chain. It elutes in the C‑window on high‑performance liquid chromatography (HPLC). We report a 10‑year‑old male with easy fatigability, lethargy, pallor, and mild splenomegaly. Hematological parameters revealed microcytic hypochromic anemia and mildly raised red blood cells count, suggestive of thalassemia trait. On HPLC, a predominant peak was observed in the C‑window (82.6%) along with raised HbA2 level (9.3%). Based on these findings, a possibility of HbC disease/β‑thalassemia trait doubly heterozygous was considered. Family studies were advised. HPLC findings in father were suggestive of β‑thalassemia trait, while both his mother and brother had an abnormal peak in the C‑window of 42.7% and 40.8%, respectively, with elevated HbA2 values of 5% and 4.9%, respectively. Direct DNA sequencing revealed intervening sequences 1–5 (G → C) in father, confirming β‑thalassemia trait. His mother and brother had heterozygous gene mutation at codon 90 of β‑globin chain (G → A) suggestive of Hb Agenogi. The child carried mutations for both β‑thalassemia trait as well as Hb Agenogi.