Invasive molecular prenatal diagnosis of alpha and beta thalassemia among Hakka pregnant women

Abstract

This study is a retrospective analysis of the prenatal genetic diagnosis results of fetuses with high risk of major thalassemia to provide information for clinical genetic counseling and to better control the birth of major thalassemia child in Hakka population. Totally, 467 fetuses in at-risk pregnancies were collected from Meizhou people's hospital from January 2014 to December 2017. Genomic DNAs were extracted from peripheral blood of the couples and villus, amniotic fluid or cord blood of the fetuses. DNA-based diagnosis was performed using polymerase chain reaction (PCR) and flow-through hybridization technique. Follow-up visits were done half a year after the fetuses were born. Around 467 fetus at-risk pregnancies were performed prenatal diagnosis. We detected 88 CVS samples, 375 amniocentesis fluid samples and, 4 cord blood samples. The 356 fetuses in α-thalassemia families consisted of 69 (19.38%) with Bart's hydrops syndrome, 20 (5.62%) fetuses with Hb H disease, and 184 (51.68%) fetuses with heterozygote. And the 111 fetuses in β-thalassemia families consisted of 31 (27.93%) thalassemia major, 51 (45.95%) fetuses with heterozygote. There are 13 fetuses with α+β-thalassemia, including 2 cases with severe β-thalassemia. DNA-based testing prenatal diagnosis of thalassemia was found to be highly reliable. Our findings provide key information for clinical genetic counseling of prenatal diagnosis for major thalassemia in Hakka pregnant women. Our work plays an important role in the prevention and control of thalassemia in Hakka population. We will also combine other techniques to further improve our molecular prenatal diagnostic capabilities, including the next-generation sequencing (NGS), Sanger sequencing and MLPA.

Gene Mutation Spectrum of Thalassemia Among Children in Yunnan Province

“…The children with low mean corpuscular volume (MCV) values (<82 fl) or low mean cell hemoglobin (MCH) values (<27 pg) were considered possible carriers of thalassemia (12).…”

New Entity—Thalassemic Endocrine Disease: Major Beta-Thalassemia and Endocrine Involvement

“…A retrospective study on 467 foetuses in at-risk pregnancies coming from the Hakka population included prenatal genetic diagnosis, which combined genomic DNAs analysis from villus, amniotic fluid or cord blood to peripheral blood of the parents (a total of 88 CVS samples, and 375 amniocentesis procedures) including 111 patients with BTH (27.93% of them with major BTH); the method provided a reliable result concerning prenatal diagnostic [ 151 ]. A secondary technique, such as NGS or Sanger sequencing, might improve the diagnostic [ 144 , 151 ].…”

Antenatal screening for haemoglobinopathies: current status, barriers and ethics

“…Amniocentesis is the best method to obtain fetal DNA at mid‐trimester (15–18 weeks’ gestation); a procedure where about 10 ml of amniotic fluid is obtained from the mother by needle aspiration and amniotic cells are obtained by centrifugation and are subjected to cell culture followed by DNA extraction and analysis (Wu et al , ). Although risk of maternal contamination is low by this method, the results take longer to obtain and may only be available when the woman is 20 weeks pregnant.…”