Analysis of real-time PCR cycle threshold of alpha-thalassemia-1 Southeast Asian type deletion using fetal cell-free DNA in maternal plasma for noninvasive prenatal diagnosis of Bart's hydrops fetalis.

Abstract

BACKGROUND:

Noninvasive prenatal diagnosis based on detection of fetal cell-free DNA is hampered when mother and father are both carriers for the same autosomal recessive mutation.

OBJECTIVE:

To compare the diagnosis of Bart's hydrops fetalis using conventional Gap-PCR analysis of fetal cells/tissues with the measurement of quantitative difference (deltaCp) between alpha-thalassemia-1 SEA type deletion gene (C(T-mutant)) and wild type alpha-globin gene (C(T-wild type)) in plasma of pregnancies by using the Taqman real-time quantitative PCR.

MATERIAL AND METHOD:

Plasma DNA samples were collected from three groups of pregnancies whose fetuses have known thalasemia status (7 normal, 11 heterozygote alpha-thalassemia-1 SEA type deletion, and 7 Bart's hydrops fetalis). The alpha-thalassemia-1 SEA type deletion gene and wild type alpha-globin gene were quantified by using Taqman real-time quantitative PCR and then the delta C(T) was analyzed by subtracting the C(T-mutant) from C(T-wild type).

RESULTS:

Mean deltaC(T) values were not significantly different among the three groups. However, women whose fetuses were diagnosed as Bart's hydrops fetalis had a higher proportion (43%) of plasma DNA samples that had negative deltaC(T) value than women whose fetuses were diagnosed as normal or heterozygote alpha-thalassemia-1 SEA type deletion (0 and 27%, respectively).

CONCLUSION:

Further investigations are needed to improve the diagnosis of Bart's hydrops fetalis using fetal cell-free DNA.

• Authors: Sakorn Pornprasert, Kanyakan Sukunthamala, Naowarat Kunyanone, Sririchai Sittiprasert, Khanungnit Thungkham, Sumeth Junorse, Khachonsilp Pongsawatkul, Wisut Pattanaporn, Chantip Jitwong, Torpong Sanguansermsri
• Journal: Journal of the Medical Association of Thailand = Chotmaihet thangphaet (J Med Assoc Thai) Vol. 93 Issue 11 Pg. 1243-8 (Nov 2010) ISSN: 0125-2208 [Print] Thailand
• PMID: 21114201 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alpha-Globulins
• Hemoglobins, Abnormal
• DNA
• hemoglobin Bart's

Topics

• Alpha-Globulins (genetics)
• Asian People (genetics)
• DNA (blood, isolation & purification)
• Female
• Fetus
• Hemoglobins, Abnormal (genetics)
• Humans
• Hydrops Fetalis (diagnosis, genetics)
• Mothers
• Plasma (chemistry)
• Polymerase Chain Reaction (methods)
• Pregnancy
• Pregnancy Trimester, First
• Pregnancy Trimester, Second
• Prenatal Diagnosis (methods)
• Sequence Deletion
• alpha-Thalassemia (blood, diagnosis, genetics)