Research article

Prevalence, phenotype and inheritance of benign neutropenia in Arabs

Srdjan Denic¹ , Saad Showqi² , Christoph Klein³ , Mohamed Takala⁴ , Nicollas Nagelkerke⁵ and Mukesh M Agarwal⁶

¹Department of Internal Medicine, Faculty of Medicine and Health Sciences, UAE University, Al Ain, UAE

²Hematology Laboratory, Department of Pathology, Al Ain Hospital, Al Ain, UAE

³Department of Pediatric Hematology/Oncology, Medical School Hannover, Hannover, Germany

⁴Staff Clinic, Al Ain Hospital, Al Ain, UAE

⁵Department of Community Medicine, Faculty of Medicine and Health Sciences, UAE University, Al Ain, UAE

⁶Department of Pathology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, UAE

author email corresponding author email

BMC Blood Disorders 2009, 9:3doi:10.1186/1471-2326-9-3

Published:	27 March 2009

Abstract

Background

Benign neutropenia, i.e., neutropenia not associated with an increased risk of infection, may result in serious medical consequences when a 'standard' definition of neutropenia (absolute neutrophil count (ANC) < 1.5 × 10⁹cells/L) is universally applied to all races. The aims of this study were to determine the prevalence of benign neutropenia among healthy Arabs and evaluate its mode of inheritance.

Methods

ANCs were studied prospectively amongst a healthy indigenous population (n = 1032) from the United Arab Emirates undergoing a nation-wide sickle-cell and thalassemia screening program. The mean neutrophil count and the prevalence of benign neutropenia were compared by age, sex and amongst various tribes.

Results

The mean neutrophil count (× 10⁹cells/L) was 3.3 (range 0.95–7.6). Benign neutropenia was present in 110 (10.7%) subjects of whom 24 (2.3%) individuals had moderate neutropenia (ANC 0.5 – 1.0 × 10⁹ cells/L). In the 22 tribe-family groups, the prevalence of benign neutropenia varied between 0% and 38%. Benign neutropenia showed no difference in the frequency amongst the sexes (p = 0.23) and it was independent of age (Spearman's rho = 0.05, p = 0.13). The age-related mean neutrophil count was the lowest in Arabs when compared with other ethnic groups (Blacks, Europeans and Mexicans). The inheritance of benign neutropenia was consistent with an autosomal dominant pattern; however, the diversity of observed phenotypes suggested the presence of more than one genetic variant for this trait.

Conclusion

Arabs have a high prevalence of benign neutropenia that may be inherited as an autosomal dominant trait.