title: Targeted sequencing approach to identify genetic mutations in Nasu-Hakola disease.
abstract: Nasu-Hakola disease (NHD) is a rare autosomal recessive disorder characterized by sclerosing leukoencephalopathy and multifocal bone cysts, caused by a loss-of-function mutation of eitherTYROBP (DAP12)orTREM2. TREM2 and DAP12 constitute a receptor/adaptor signaling complex expressed exclusively on osteoclasts, dendritic cells, macrophages, and microglia. Premortem molecular diagnosis of NHD requires genetic analysis of bothTYROBPandTREM2, in which 20 distinct NHD-causing mutations have been reported. Due to genetic heterogeneity, it is often difficult to identify the exact mutation responsible for NHD. Recently, the revolution of the next-generation sequencing (NGS) technology has greatly advanced the field of genome research. A targeted sequencing approach allows us to investigate a selected set of disease-causing genes and mutations in a number of samples within several days. By targeted sequencing using the TruSight One Sequencing Panel, we resequenced genetic mutations of seven NHD cases with known molecular diagnosis and two control subjects. We identified homozygous variants ofTYROBPorTREM2in all NHD cases, composed of a frameshift mutation of c.141delG in exon 3 ofTYROBPin four cases, a missense mutation of c.2T>C in exon 1 ofTYROBPin two cases, or a splicing mutation of c.482+2T>C in intron 3 ofTREM2in one case. The results of targeted resequencing corresponded to those of Sanger sequencing. In contrast, causative variants were not detected in control subjects. These results indicate that targeted sequencing is a useful approach to precisely identify genetic mutations responsible for NHD in a comprehensive manner.
authors.affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Satoh
authors.affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Yanaizu
authors.affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan.
authors.forename: Youhei
authors.initials: Y
authors.lastname: Tosaki
authors.affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakai
authors.affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kino
keywords: DAP12; Nasu-Hakola disease; TREM2; TYROBP; targeted sequencing