RT Journal Article SR Electronic T1 Abnormally Low Hemoglobin A1c as Harbinger of Hemoglobinopathy JF The Journal of the American Board of Family Medicine JO J Am Board Fam Med FD American Board of Family Medicine SP 923 OP 924 DO 10.3122/jabfm.2019.06.190124 VO 32 IS 6 A1 St. Louis, Joshua A1 Valdini, Anthony YR 2019 UL http://www.jabfm.org/content/32/6/923.abstract AB Hemoglobin A1c is frequently used in primary care to screen for and monitor disorders of glucose metabolism. A number of clinical syndromes may impact the accuracy of this laboratory value. This report describes a case of abnormally low hemoglobin A1c that was the result of an asymptomatic compound hemoglobinopathy (homozygous hemoglobin S disease and hereditary persistence of fetal hemoglobin) that had gone previously undiagnosed. Primary care physicians must be aware of such pitfalls in the use of this laboratory value and be prepared to use other values to monitor for and assess disorders of glucose metabolism.