Gan-Or Z, Bouslam N, Birouk N, Lissouba A, Chambers DB, Vérièpe J, Androschuck A, Laurent SB, Rochefort D, Spiegelman D, Dionne-Laporte A, Szuto A, Liao M, Figlewicz DA, Bouhouche A, Benomar A, Yahyaoui M, Ouazzani R, Yoon G, Dupré N, Suchowersky O, Bolduc FV, Parker JA, Dion PA, Drapeau P, Rouleau GA, Bencheikh BO. Mutations in CAPN1 Cause Autosomal-Recessive Hereditary Spastic Paraplegia. Am J Hum Genet. 2016 May 5;98(5):1038-46. PMID: 27153400.
From the abstract: "Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous disease characterized by spasticity and weakness of the lower limbs with or without additional neurological symptoms. Although more than 70 genes and genetic loci have been implicated in HSP, many families remain genetically undiagnosed, suggesting that other genetic causes of HSP are still to be identified. HSP can be inherited in an autosomal-dominant, autosomal-recessive, or X-linked manner. In the current study, we performed whole-exome sequencing to analyze a total of nine affected individuals in three families with autosomal-recessive HSP. Rare homozygous and compound-heterozygous nonsense, missense, frameshift, and splice-site mutations in CAPN1 were identified ... CAPN1 encodes calpain 1, a protease that is widely present in the CNS. ... Three models of calpain 1 deficiency were further studied. In Caenorhabditis elegans, loss of calpain 1 function resulted in neuronal and axonal dysfunction and degeneration. Similarly, loss-of-function of the Drosophila melanogaster ortholog calpain B caused locomotor defects and axonal anomalies. Knockdown of calpain 1a, a CAPN1 ortholog in Danio rerio, resulted in abnormal branchiomotor neuron migration and disorganized acetylated-tubulin axonal networks in the brain. The identification of mutations in CAPN1 in HSP expands our understanding of the disease causes and potential mechanisms."