biostudies-literatureLi HNational Natural Science Foundation of Chinae963https://www.ebi.ac.uk/biostudies/studies/S-EPMC6825866biostudies-literatureUnknown7(11)<h4>Background</h4>β-thalassemia is one of the most common monogenic diseases in the world. Southeast China is a highly infected area affected by four β-thalassemia mutation types (HBB:c.-78A>G, HBB:c.52A>T, HBB:c.126_129delCTTT, and HBB:c.316-197C>T). Relative haplotype dosage (RHDO), a haplotype-based approach, has shown promise as an application for noninvasive prenatal diagnosis (NIPD); however, additional family members (such as the proband) are required for haplotype construction. The abovementioned circumstances make RHDO-based NIPD cost prohibitive; additionally, the genetic information of the proband is not always available. Thus, it is necessary to find a practical method to solve these problems.<h4>Methods</h4>Targeted sequencing was applied to sequence parental genomic DNA and cell-free fetal DNA (cffDNA). Parental haplotypes were constructed with the SHAPEIT software based on the 1000 Genomes Project (1000G) Phase 3 v5 Southern Han Chinese (CHS) haplotype dataset. Single-nucleotide polymorphisms (SNPs) in the target region were called and classified, and the fetal mutation inheritance status was deduced using the RHDO method.<h4>Results</h4>Construction of the parental haplotypes and detection of the inherited parental mutations were successfully achieved in five families, despite a suspected recombination event. The status of the affected fetuses is consistent with the results of traditional reverse dot blot (RDB) diagnosis.<h4>Conclusion</h4>This research introduced SHAPEIT into the classical RHDO workflow and proved that it is applicable to construct parental haplotypes without information from other family members.Molecular genetics & genomic medicineNoninvasive prenatal diagnosis of β-thalassemia by relative haplotype dosage without analyzing proband.PMC682586681270745Ouyang SLi HXie YJiang FGuo YChen MXian YZeng XSun XLiu WDu BWang YZhang CfalseNoninvasive prenatal diagnosis of β-thalassemia by relative haplotype dosage without analyzing proband.<h4>Background</h4>β-thalassemia is one of the most common monogenic diseases in the world. Southeast China is a highly infected area affected by four β-thalassemia mutation types (HBB:c.-78A>G, HBB:c.52A>T, HBB:c.126_129delCTTT, and HBB:c.316-197C>T). Relative haplotype dosage (RHDO), a haplotype-based approach, has shown promise as an application for noninvasive prenatal diagnosis (NIPD); however, additional family members (such as the proband) are required for haplotype construction. The abovementioned circumstances make RHDO-based NIPD cost prohibitive; additionally, the genetic information of the proband is not always available. Thus, it is necessary to find a practical method to solve these problems.<h4>Methods</h4>Targeted sequencing was applied to sequence parental genomic DNA and cell-free fetal DNA (cffDNA). Parental haplotypes were constructed with the SHAPEIT software based on the 1000 Genomes Project (1000G) Phase 3 v5 Southern Han Chinese (CHS) haplotype dataset. Single-nucleotide polymorphisms (SNPs) in the target region were called and classified, and the fetal mutation inheritance status was deduced using the RHDO method.<h4>Results</h4>Construction of the parental haplotypes and detection of the inherited parental mutations were successfully achieved in five families, despite a suspected recombination event. The status of the affected fetuses is consistent with the results of traditional reverse dot blot (RDB) diagnosis.<h4>Conclusion</h4>This research introduced SHAPEIT into the classical RHDO workflow and proved that it is applicable to construct parental haplotypes without information from other family members.2019-01-01T00:00:00Z2019 Nov2025-04-05T13:30:36.575Z2019-11-15T08:05:03ZS-EPMC68258663156692910.1002/mgg3.963