Hayato Tada1, Mika Hori2, Akihiro Nomura1, Kazuyoshi Hosomichi3, Atsushi Nohara4, Masa-Aki Kawashiri5, Mariko Harada-Shiba2. 1. Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan. 2. Department of Molecular Innovation in Lipidology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan. 3. Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa, Japan. 4. Department of Genetics, Ishikawa Prefectural Central Hospital, Kanazawa, Japan. 5. Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan. Electronic address: mk@med.kanazawa-u.ac.jp.
Abstract
BACKGROUND: Little data exist on the pathogenic mutations of LDL receptor in Japanese familial hypercholesterolemia (FH). OBJECTIVE: We aimed to catalog the pathogenic mutations of LDL receptor gene in the 2 major Japanese FH-care centers (Kanazawa University and National Cerebral and Cardiovascular Center Research Institute), where genetic testing of FH has been performed centrally on requests from institutes all over Japan during more than past 2 decades. METHODS: 796 FH subjects from 472 families who had nonsynonymous mutations in LDL receptor gene were included in this study. Genetic mutations were analyzed for mutations by Sanger sequencing as well as by multiplex ligation probe dependent amplification technique for large rearrangements. Pathogenic mutations were defined either as 1) protein truncated variants, 2) registered as pathogenic in ClinVar, or Human Gene Mutation Database (HGMD), or meet the criteria of American College of Medical Genetics and Genomics guideline, or 3) CADD score > 10. RESULTS: We found 138 different mutations. Among them, 132 mutations were considered as pathogenic, including 19 large rearrangement mutations. However, 6 missense mutations were classified as variants of unknown significance. A single mutation accounted for as much as 41% of the FH subjects recruited from Kanazawa University mainly due to founder gene effect, whereas many singleton mutations were found from National Cerebral and Cardiovascular Center Research Institute located in Osaka. CONCLUSIONS: We provided the largest catalog of pathogenic mutations of LDL receptor gene in Japanese FH. This could aid to determine the pathogenicity of the LDL receptor genetic mutations not only in Japanese but also in other ethnicities.
BACKGROUND: Little data exist on the pathogenic mutations of LDL receptor in Japanese familial hypercholesterolemia (FH). OBJECTIVE: We aimed to catalog the pathogenic mutations of LDL receptor gene in the 2 major Japanese FH-care centers (Kanazawa University and National Cerebral and Cardiovascular Center Research Institute), where genetic testing of FH has been performed centrally on requests from institutes all over Japan during more than past 2 decades. METHODS: 796 FH subjects from 472 families who had nonsynonymous mutations in LDL receptor gene were included in this study. Genetic mutations were analyzed for mutations by Sanger sequencing as well as by multiplex ligation probe dependent amplification technique for large rearrangements. Pathogenic mutations were defined either as 1) protein truncated variants, 2) registered as pathogenic in ClinVar, or Human Gene Mutation Database (HGMD), or meet the criteria of American College of Medical Genetics and Genomics guideline, or 3) CADD score > 10. RESULTS: We found 138 different mutations. Among them, 132 mutations were considered as pathogenic, including 19 large rearrangement mutations. However, 6 missense mutations were classified as variants of unknown significance. A single mutation accounted for as much as 41% of the FH subjects recruited from Kanazawa University mainly due to founder gene effect, whereas many singleton mutations were found from National Cerebral and Cardiovascular Center Research Institute located in Osaka. CONCLUSIONS: We provided the largest catalog of pathogenic mutations of LDL receptor gene in Japanese FH. This could aid to determine the pathogenicity of the LDL receptor genetic mutations not only in Japanese but also in other ethnicities.