Prevalence of Thalassemia Carriers of Foreign Spouses Attending at the Antenatal Clinic, Metropolitan Health and Wellness Institution, Bangkok

Abstract

Thalassemia is  one  of  the genetic  disorders considered  to be a serious  health issue  in

Thailand. The proportion of thalassemia carriers in the Thai population differs from one region to

another. Each year, more than 10,000  new thalassemia cases are diagnosed,  some of which have

severe anemic symptoms. Currently, Thailand is facing the settlement of many migrant workers from

neighboring countries, thus, it is very important to assess the prevalence of thalassemia carriers, as

well as the possibility of newborns with severe thalassemia conditions in this population. In this study,

the data of thalassemia diagnosis in migrant workers were collected from January to December 2019

at the Metropolitan Health and Wellness Institution’s Antenatal Care Clinic in Bangkok. The total

number of 162 (81 couples) migrants were recruited with 56 (34.57%) Burmese, 58 (35.80%) Laos

and 48  (29.63%)  Cambodian. Diagnosis  of beta-thalassemia was carried out using the capillary

electrophoresis while alpha-thalassemia-1 SEA and THAI type deletions were analyzed by real -time

PCR. The results from 162 migrants showed that there were 5 (3.09%) with beta-thalassemia  trait,

54 (33.33%)  with HbE trait, 3 (1.85%) with double heterozygous alpha-thalassemia-1 SEA type

deletion and HbE trait, 12 (7.41%) with homozygous  HbE and 8 (4.94  %) with alpha-thalassemia-1

SEA type deletion  trait. In addition,  one couple  from Laos was found to carry a risk of having a new

born with beta-thalassemia/HbE  disease. When the Hardy-Weinberg  Formula (HWF) was used to

genetically  estimate the  number of  the  new  born with  severe  thalassemia diseases  per 10,000

pregnancies, it was predicted that 3  babies would  be born with homozygous  beta-thalassemia,

75 with beta-thalassemia/HbE disease and 12 with Hb Bart’s hydrops fetalis. Taken together, these

data suggest that the intensive control, prevention and management of thalassemia diseases at the

national level are very important issue to be implemented.