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Neuromuscul Disord DOI:10.1016/j.nmd.2014.04.010

Whole exome sequencing identifies three recessive FIG4 mutations in an apparently dominant pedigree with Charcot-Marie-Tooth disease.

Publication TypeJournal Article
Year of Publication2014
AuthorsMenezes, MP, Waddell, L, Lenk, GM, Kaur, S, MacArthur, DG, Meisler, MH, Clarke, NF
JournalNeuromuscul Disord
Date Published2014 Aug
KeywordsAdolescent, Adult, Charcot-Marie-Tooth Disease, Codon, Nonsense, Dystrophin, Family, Female, Flavoproteins, Genes, Recessive, Heterozygote, Humans, Pedigree, Phosphoric Monoester Hydrolases, Severity of Illness Index

Charcot-Marie-Tooth disease (CMT) is genetically heterogeneous and classification based on motor nerve conduction velocity and inheritance is used to direct genetic testing. With the less common genetic forms of CMT, identifying the causative genetic mutation by Sanger sequencing of individual genes can be time-consuming and costly. Next-generation sequencing technologies show promise for clinical testing in diseases where a similar phenotype is caused by different genes. We report the unusual occurrence of CMT4J, caused by mutations in FIG4, in a apparently dominant pedigree. The affected proband and her mother exhibit different disease severities associated with different combinations of compound heterozygous FIG4 mutations, identified by whole exome sequencing. The proband was also shown to carry a de novo nonsense mutation in the dystrophin gene, which may contribute to her more severe phenotype. This study is a cautionary reminder that in families with two generations affected, explanations other than dominant inheritance are possible, such as recessive inheritance due to three mutations segregating in the family. It also emphasises the advantages of next-generation sequencing approaches that screen multiple CMT genes at once for patients in whom the common genes have been excluded.


Alternate JournalNeuromuscul. Disord.
PubMed ID24878229
PubMed Central IDPMC4096049
Grant ListR01 GM024872 / GM / NIGMS NIH HHS / United States
R01 GM24872 / GM / NIGMS NIH HHS / United States