β-thalassemia is an autosomal recessive disease with the reduction or absence in the production of β-globin chain in the hemoglobin, which is caused by mutations in the Hemoglobin subunit beta (HBB) gene. In Vietnam, the number of β-thalassemia carriers range from 1.5 to 25.0%, depending on ethnic and geographical areas, which is much higher than WHO’s data worldwide (1.5%). Hence, preimplantation genetic diagnosis (PGD) plays a crucial role in reducing the rate of β-thalassemia affected patients/carriers. In this research, we report the feasibility and reliability of conducting PGD in combination with the use of short tandem repeat (STR) markers in facilitating the birth of healthy children. Six STRs, which were reported to closely linked with the HBB gene, were used on 15 couples of β-thalassemia carriers. With 231 embryos, 168 blastocysts were formed (formation rate of 72.73%), and 88 were biopsied and examined with STRs haplotyping and pedigree analysis. Thus, the results were verified by Sanger sequencing, as a definitive diagnosis. Consequently, 11 over 15 couples have achieved pregnancy of healthy or at least asymptomatic offspring. Only three couples failed to detect any signs of pregnancy such as increased Human Chorionic Gonadotropin (HCG) level, foetal sac, or heart; and one couple has not reached embryo transfer as they were proposed to continue with HLA-matching to screen for a potential umbilical cord blood donor sibling. Thus, these results have indicated that the combination of PGD with STRs analysis confirmed by Sanger sequencing has demonstrated to be a well-grounded and practical clinical strategy to improve the detection of β-thalassemia in the pregnancies of couples at-risk before embryo transfer, thus reducing β-thalassemia rate in the population.

Limb-girdle muscular dystrophies (LGMDs) are a heterogeneous group of rare genetic disorders, characterized by progressive weakness and muscle wasting. Currently, more than 27 different muscular disorders are identified as subtypes of LGMDs. Derived from the inheritance manners, LGMDs were classified into two main types: LGMD type 1 (autosomal dominant: AD) and LGMD type 2 (autosomal recessive: AR). 1 LGMD2 shows a more common distribution, with a prevalence of 1: 15,000, than LGMD1 (<10% of all LGMD cases). 2 Moreover, LGMD2 has been investigated to be associated with mutations from a group of sarcoglycanopathies genes such as SGCG, SGCA, SGCB, SGCD genes, which cause several subtypes of LGMD2 including LGMD2C to F, respectively.