Pelger-Huet Anomaly

Pelger-Huet anomaly (PHA) is an inherited blood condition in which the nuclei of several types of white blood cells (neutrophils and eosinophils) have unusual shape (bilobed, peanut or dumbbell-shaped instead of the normal trilobed shape) and unusual structure (coarse and lumpy).  Click here to view a picture of these cells seen under the microscope. PHA is considered to be a benign disorder in most instances, as individuals with PHA are typically healthy. PHA is caused by mutations in the LBR gene. It is suspected that mutations within the LBR gene are responsible for a spectrum of disorders including isolated PHA; PHA with mild skeletal symptoms; and Hydrops, Ectopic calcification, Moth-eaten skeletal dysplasia (HEM). PHA was previously thought to be inherited in an autosomal dominant manner; however, co-dominant inheritance has been suggested as well. It is important to distinguish PHA from acquired or pseudo-Pelger-Huet anomaly, which may be found in individuals with certain types of leukemia or myelodysplastic syndromes. Diagnosis is made based on characteristic appearance of white blood cell nuclei identified by a blood smear. Most individuals with PHA do not require treatment as they do not have symptoms.