Prevalence of Hemoglobinopathies Among the Kurdish Population in Zakho City, Kurdistan Region, Iraq.

BACKGROUND

Hemoglobinopathies are the most common inherited disorders in the Mediterranean region, including Iraq, with different frequencies and molecular features. They represent an important health problem in Iraq. Several studies have addressed the prevalence of hemoglobinopathy in Iraq, but no specific research has addressed its prevalence in Zakho city, Kurdistan Region, Iraq. Thus, this study was conducted to address this issue.

MATERIALS AND METHODS

A prospective cross-sectional study was conducted in a premarital screening center at Zakho Emergency Teaching Hospital, involving 11,910 Kurdish persons attending premarital screening investigations. Blood samples were collected from all participants for complete blood counts and sickling tests. A cut-off value of hemoglobin (Hb) concentrations (<13.0 gm/dl in males, <12.0 gm/dl in females), mean cell volume (MCV) <80 fl and/or mean cell hemoglobin (MCH) <27 pg, and the results of the sickling test were used to categorize the participants into three groups: group I, normal (normal Hb, MCV, and MCH, and negative sickling test); group II, individuals with MCV < 80 fl and/or MCH < 27 pg, with or without anemia, and negative sickling test; group III, sickle positive (individuals with a positive sickling test, with or without anemia, regardless of MCV and/or MCH values). Groups II and III underwent further evaluations by morphology, reticulocyte count, hemoglobin-H preparation, iron studies, and cation exchange high-performance liquid chromatography (HPLC). β-thalassemia trait was diagnosed by hypochromic microcytic red cell indices and increased hemoglobin A2 (HbA2) (>3.5%). The sickle cell trait was diagnosed by the presence of a band at the S region at HPLC with a positive sickling test. Iron deficiency anemia (IDA) was diagnosed by hypochromic microcytic anemia and reduced transferrin saturation (<15%) and/or ferritin (<15 mg/L). Descriptive statistical analyses were conducted to define significant differences between the study's findings.

RESULTS

A total of 963 (8.09%) of the studied participants were in group II. Further investigations on these 963 cases confirmed a diagnosis of IDA in 610 (5.12%). β-thalassemia trait was detected in 308 cases, with an overall prevalence of 2.59%. δβ-thalassemia trait was detected in nine (0.076%) of the studied participants. A professional diagnosis of α-thalassemia was given to 36 (0.30%) of those with hypochromic microcytic red cell indices, normal iron studies, and HPLC results. A positive sickling test was seen in 48 participants and confirmed by HPLC as a sickle cell trait with a prevalence of 0.4%. The consanguinity rate among couples was 28.8%. Neither case of HbC or HbD trait, nor combined hemoglobinopathy, was detected in the current study. Furthermore, no differences were found between the prevalence of both β thalassemia and sickle cell trait with either sex and/or religion, with a p-value of 0.07, 0.07, 0.532, and 0.78, respectively.

CONCLUSION

The prevalence of hemoglobinopathy in Zakho city is lower than in other regions of Iraq but still constitutes a significant burden on health services and financial resources. Careful interpretations of red cell indices, together with intensified premarital screening and counseling programs, coupled with an urgent need to increase awareness about the effects of consanguinity marriages on the prevalence of autosomal recessive disorders, can further reduce the incidence of hemoglobinopathies.