Hb Shepherds Bush (HBB:c.224G > A) is an unstable hemoglobin molecule resulting from a β 74 GCC to GAC point mutation (Gly to Asp). Hb Shepherds Bush, although initially reported in a South African woman of English extraction , has since been found in patients of only Sicilian [3, 4, 8] or Spanish  decent. This case thus illustrates the potentially variable genetic diversity of the condition. Our patient’s family identifies itself as of English heritage, however there is no direct evidence of a common English ancestry link with the first reported case of Hb Shepherds Bush . Her case, however, is the first recorded in North America where her family has resided for several generations making her unique.
When patients present with the symptoms of an acute hemolytic episode—fatigue, hepatosplenomegaly, dark urine, scleral icterus and abdominal pain —a systematic algorithm should be utilized to determine the cause of their presentation. In the setting of acute anemia—demonstrated on CBC and reticulocyte percentage—hemoglobinopathies should be considered only after ruling out treatable causes such as drugs, infection (via negative cultures) or autoantibodies (via a negative Direct Coombs test) which can also produce the aforementioned symptoms. If the above are ruled out—and laboratory tests indicate anemia, reticulocytosis and signs of active hemolysis—then the physician should begin to consider a congenital hemoglobinopathy as a possible diagnosis.
If abnormal hemoglobin is suspected, then a battery of tests should be used to determine the specific hemoglobin variant. Alkaline hemoglobin electrophoresis on cellulose acetate is commonly used to identify major hemoglobin variants with acidic pH electrophoresis on citrate agar often utilized as an auxiliary step to distinguish among hemoglobin variants that co-migrate under alkaline conditions. If higher resolution is needed when using electrophoresis, methods such as isoelectric focusing can be explored. In our patient’s case, isoelectric focusing was not necessary to distinguish the presence of an abnormal hemoglobin. Under alkaline conditions, Hb Shepherds Bush separates from HbA and migrates in a manner similar to HbJ.
If electrophoresis is positive for an unknown hemoglobin variant, then HPLC (both cation exchange and reverse phase) should be utilized to evaluate rare hemoglobinopathies. In addition to chronicling elution times for identification of the hemoglobin variant, HPLC also provides percent compositions of blood samples. CE can also provide a quantitative evaluation of hemoglobin types [10, 11].
In the evaluation of our patient, CE was performed initially per our institution’s standard operating procedures as an automated and high-throughput screening tool. After positive results were obtained using CE, the patient’s blood sample was sent to a reference laboratory for further analysis where alkaline gel electrophoresis was performed along with HPLC, each showing migration of an unknown hemoglobin variant.
If HPLC or CE is positive for an unknown hemoglobin variant, PCR, which can be performed on genomic DNA extracted from a peripheral blood sample, should be used to determine genetically the hemoglobinopathy of study [12–14]. PCR sequencing can be utilized to find the abnormal mutations that generate the variant hemoglobin causing the hemoglobinopathy. In our patient, PCR sequencing showed the β 74 GCC to GAC point mutation (Gly to Asp) mutation specific to Hb Shepherds Bush.
When our patient’s specific hemoglobinopathy was elucidated, the patient was treated symptomatically with packed red blood cell transfusions. Long-term treatment plans should avoid iron supplementation and frequent transfusions as to prevent iron overload. Patients should also be watched carefully for gall bladder disease caused by calcium bilirubinate precipitating as pigmented bile stones .
Our patient’s case demonstrates a classic finding of hemolytic anemia caused by an unstable hemoglobin variant. Although Hb Shepherds Bush is uncommon, the diagnosis of this disease illustrates progression through a systematic algorithm of tests to consider when dealing with possible congenital hemoglobinopathies of unknown characterization. The first reported case of Hb Shepherds Bush in a North American family and in a patient of non-Sicilian, non-Spanish descent, this case illustrates an increased geographic and genetic diversity of the disease of Hb Shepherds Bush, and it demonstrates a diagnostic approach to unknown hemoglobinopathies.
Written informed consent was obtained from the patient and patient’s legal guardian for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.