Molecular Diagnosis of Craniosynostosis Using Targeted Next-Generation Sequencing

Abstract

Background: Genetic factors play an important role in the pathogenesis of craniosynostosis (CRS). However, the molecular diagnosis of CRS in clinical practice is limited because of its heterogeneous etiology. Objective: To investigate the genomic landscape of CRS in a Korean cohort and also to establish a practical diagnostic workflow by applying targeted panel sequencing. Methods: We designed a customized panel covering 34 CRS-related genes using in-solution hybrid capture method. We enrolled 110 unrelated Korean patients with CRS, including 40 syndromic and 70 nonsyndromic cases. A diagnostic pipeline was established by combining in-depth clinical reviews and multiple bioinformatics tools for analyzing single-nucleotide variants (SNV)s and copy number variants (CNV)s. Results: The diagnostic yield of the targeted panel was 30.0% (33/110). Twenty-five patients (22.7%) had causal genetic variations resulting from SNVs or indels in 9 target genes (TWIST1, FGFR3, TCF12, ERF, FGFR2, ALPL, EFNB1, FBN1, and SKI, in order of frequency). CNV analysis identified 8 (7.3%) additional patients with chromosomal abnormalities involving 1p32.3p31.3, 7p21.1, 10q26, 15q21.3, 16p11.2, and 17p13.3 regions; these cases mostly presented with syndromic clinical features. Conclusion: The present study shows the wide genomic landscape of CRS, revealing various genetic factors for CRS pathogenesis. In addition, the results demonstrate that an efficient diagnostic workup using target panel sequencing provides great clinical utility in the molecular diagnosis of CRS. Keywords: Chromosomal abnormalities; Congenital anomaly; Craniosynostosis; Genetic diagnosis; Massively parallel sequencing.