What Is a Pelger-Huet Anomaly?

Pelger-Huet anomaly is an unusual inherited blood disorder where white blood cells known as neutrophils have an abnormal shape. It is caused by changes on the lamin B receptor gene, which alters the shape of the cell nucleus and the distribution of chromatin, the package of proteins and DNA that carries genetic materials. A pathologist can identify Pelger-Huet anomaly on a blood sample from a patient, as the neutrophils will have a very distinctive appearance. Testing may be recommended if one or both parents have the condition as it can be useful to know about for future reference, or it may explain why a patient is experiencing medical problems.

This condition is dominant, requiring only one copy of the gene for it to be expressed. In people who are heterozygous for the trait, meaning they inherited one defective gene and one normal one, Pelger-Huet anomaly is benign. The nuclei of the neutrophils have a distinctive double-lobed appearance with chunks of clumped chromatin. It can cause some abnormalities on blood tests, which makes it important to know about if the patient is being evaluated for disease.

Homozygous individuals have both copies of the gene, and are more at risk of medical problems as a result. The nucleus takes on a roughly circular shape, making it easy to differentiate from the other form of the condition. Patients can develop skeletal abnormalities, seizures, and increased susceptibility to infection, and may have a shorter life expectancy as a result. In some cases, the Pelger-Huet anomaly is fatal because it may be associated with other genetic issues.

Treatment options for patients with malignant Pelger-Huet anomaly can depend on the symptoms. They are typically based on keeping the person comfortable and addressing issues like seizures as they arise. Medications, for example, can help control seizures, reducing their frequency and severity to reduce the risk of injuries. To protect patients from infection, it may be necessary to observe some precautions, and prophylactic antibiotics may be recommended in some settings to ensure that patients don’t get sick after exposures to potentially infectious organisms.

Patients can also develop a condition known as acquired or pseudo Pelger-Huet anomaly, where their cells change structure but they don’t have the true genetic condition. In these situations, previous blood work will show normal white blood cells, but followups will have cells with the characteristic differences associated with this condition. This can occur in conjunction with blood cancers and some other medical disorders.