Novel and known microsatellite markers within the β-globin cluster to support robust preimplantation genetic diagnosis of β-thalassemia and sickle cell syndromes.
Preimplantation genetic diagnosis (PGD) for β hemoglobinopathies has become the most common application among monogenic disorders. We present the identification of microsatellite markers [short tandem repeats (STRs)] closely linked to the β-globin gene for incorporation within PGD protocols, with the aim of increasing the number of transferable embryos. Nine candidate STRs were identified in-silico, of which three were selected based on rate-of-heterozygosity, polymerase chain reaction (PCR) efficiency and size. The multiplex reaction (β-globin gene and selected STRs, all within <0.4 Mb from the β gene) was optimized in single lymphocytes, and subsequently applied in 38 PGD cycles in couples at-risk for transmitting β hemoglobinopathies. In conclusion, incorporation of closely linked polymorphic microsatellite markers <0.4 Mb from the β-globin gene, facilitates robust assignment of β hemoglobinopathy genotypes, increasing the number of transferrable embryos otherwise rejected due to allele-drop-out (ADO), at the mutation-specific locus, compared to results based on disease-mutation genotyping alone (p < 0.001).
Department of Medical Genetics, Athens University, St. Sophia's Children's Hospital, Athens, Greece.
Sophia
S
Zachaki
Christina
C
Vrettou
Aspasia
A
Destouni
Ggeorgia
G
Kokkali
Joanne
J
Traeger-Synodinos
Emmanuel
E
Kanavakis
D000483:Alleles; D000755:Anemia, Sickle Cell / Q000175:diagnosis / Q000196:embryology / Q000235:genetics*; D001757:Blastomeres; D020732:Cytogenetic Analysis; D004624:Embryo Transfer; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods; D059010:Single-Cell Analysis / Q000379:methods; D013577:Syndrome; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000175:diagnosis / Q000196:embryology / Q000235:genetics*
D055544:beta-Globins