Abstract

Reconstruction of parental haplotypes is a major step in noninvasive prenatal testing (NIPT) for singlegene disorders (1). Indirect haplotyping, based on genotypes of the mother, father, and proband, is challenging when the genotype of the proband is unavailable (2). A 2017 study by Hui et al. made a progress in NIPT for single-gene disorders through direct haplotyping using linked-read sequencing (10 X genomics), thereby resolving the drawback of indirect haplotyping (3). This method has been applied successfully to several monogenic disorders such as congenital adrenal hyperplasia and hemophilia (3). However, this approach warrants further examination to establish its clinical applicability to a range of single-gene disorders.