Hematologic genetic disorders among Southeast Asian refugees

Abstract

Resettlement of Southeast Asian refugees has introduced into the Western Hemisphere many persons of all major ethnic groups from Indochina. They represent several distinctive cultural, genetic, and linguistic groups, and the prevalence of genetic traits among them varies accordingly. We studied 778 Southeast Asian persons resettled in the upper Midwest who belonged to 182 unrelated families from the five major Southeast Asian ethnic groups. High prevalences of hemoglobin E, alpha- and beta-thalassemia disorders, and glucose-6-phosphate dehydrogenase deficiency were found. The prevalences of these four conditions in the refugees are among the highest known in the world. For these groups, iron deficiency is an uncommon cause of microcytosis; instead, the most frequent causes are hemoglobin E and alpha-thalassemia-1. Very serious thalassemic disorders occur with unusually high frequency in the refugees, especially in the Tai-Dam.

Haemoglobin Disorders among Southeast-Asian Refugees in France

“…As expected, haemoglobinopathies are frequent mostly among laotians and Cambodians [3]. Hb E and a-thalassaemia are the two predominant defects [4,5] and they seem to have some interaction.…”

Hemoglobin E: An emerging hemoglobinopathy in the United States

“…In Southeast Asian immigrants, the prevalence of Hb E ranges from 36 and 31 % , respectively, for those of Lao Loum (Laotian) and Khmer (Cam- bodian) background to 2-4 % in Vietnamese and the Hmong [5] ( Table 1). It has been estimated that the overall prevalence of Hb E in Southeast Asian refugees will be approximately 10% [5].…”

“…In 1979, Fairbanks et a1 reported the first cases of Hb E in Southeast Asians who had emigrated to the United States [8]. Large numbers of these individuals have settled in such diverse (and malaria-free) areas as Minnesota [5,7], Iowa, Wisconsin, Illinois, North and South Dakota [5,9], Connecticut [6], and northern and southern California [10,29]. In Southeast Asian immigrants, the prevalence of Hb E ranges from 36 and 31 % , respectively, for those of Lao Loum (Laotian) and Khmer (Cam- bodian) background to 2-4 % in Vietnamese and the Hmong [5] ( Table 1).…”

Newborn Screening for Hemoglobin Abnormalities: A Comparison of Methods

“…7 These frequencies of one alpha globin gene deletion are much greater than the detection of Hb Bart's on IEF or CAC electrophoresis. Although we suspect that the discrepancies between CAC and IEF reflect the improved ability of IEF to detect the one alpha globin gene deletion state, any conclusions are conjectural without concomitant DNA analysis.…”