--- license: permission_granted topic_id: companion_breed_health_maine_coon_polydactyl_omia4605_cat category: companion-breed-health title: "Maine Coon Polydactyl — Spinal muscular atrophy, LIX1-related (hereditary; OMIA-verified breed predisposition)" lang: en source: "OMIA (Online Mendelian Inheritance in Animals, University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-02 from local OMIA database dump." source_file: pdf-raw/breed-health/maine_coon_polydactyl_omia4605_4605.txt date_parsed: 2026-08-02 tokens_estimated: 921 verification: method: substring_match claims: 8 passed: 8 date: 2026-08-02 recovered: false path: companion-breed-health/companion_breed_health_maine_coon_polydactyl_omia4605_cat/01_companion_breed_health_maine_coon_polydactyl_omia4605_cat.md source_document: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" citation: authority: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" title: "Maine Coon Polydactyl — Spinal muscular atrophy, LIX1-related (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA002389/9685/" retrieved: "2026-08-02" ref: "OMIA breed-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70" doc_type: "academic animal-genetics database (breed-specific disorder entries)" needs_review: false
Maine Coon Polydactyl — Spinal muscular atrophy, LIX1-related (hereditary; OMIA-verified breed predisposition)
Source: first-hand OMIA (University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; every claim below is a C1 byte-substring of it.
Claims
Breed: Maine Coon Polydactyl (Cat)Disorder:Mode of inheritance: Autosomal recessiveSummary: Information relating to feline spinal muscular atrophy due to likely causal variants in the LIX1 gene has been moved from the generic 'a href=https://www.omia.org/OMIA000939/9685/OMIA:000939-9685/a : Spinal muscular atrophy in Felis catus' entry to this page [19/08/2021] Feline spinal muscular atrophy is a neurogenic disease characterized by progressive gait abnormalities, weakness, and atrophy of limb muscles. It is present in Maine Coon cats. Signs appear between 13 and 17 weeks of age, and include gait abnormalities, tremors, weakness, muscle atrophy, elevations of creatine phosphokinase activity, and abnormal electrical activity of muscles on EMG. Pathologic changes are consistent with muscle denervation, which is due to lower motor neuron loss. The mode of inheritance is autosomal recessive. The causative mutation is a deletion removing portions of LIX1 and LNPEP. There is a test available to detect the mutation. Maine Coon cats used for breeding should be tested for the causative mutation. Affected cats should not be bred. Carriers should only be bred to tested cats demonstrated to be noncarriers. Edited by John C. Fyfe, D.V.M., Ph.D.Clin feat: Affected cats begin to show signs between 13 and 17 weeks of age. Signs include gait abnormalities, and a muscle tremor primarily involving the hindquarters. Limb weakness is progressive for several months. By five months of age, muscle atrophy is evident in all limbs, and affected cats show a characteristic gait of wide-placed forelimbs and swaying pelvis. Disease progression slows around 4-8months and affected cats with varying severity of clinical signs lived for at least 8 years of age (He et al., 2005). Creatine phosphokinase activity is elevated 2 to 3 fold in affected cats. Pelvic and pectoral girdle muscles and thoraco-lumbar epaxial muscles show mild to moderate insertional activity with fibrillation potentials and positive sharp waves on EMG. However, motor nerve conduction velocities of the sciatic nerves are normal (He et al., 2005). [IT thanks DVM student Jacqualine Yue for suggested changes in April 2022]Defect: yesPathology: Affected animals are deficient in LNPEP and LIX1. LNPEP is a widely distributed enzyme of the endoplasmic reticulum that processes peptides for antigen presentation. The function of LIX1 is unknown, but it is highly conserved and mostly expressed in spinal cord neurons. It is probably necessary for neuron development and maintenance (Fyfe et al., 2006). Pathologic changes are consistent with muscle denervation, which is due to lower motor neuron loss. Histopathology on hindlimb muscle samples from affected cats shows variation in myofiber size with many angular atrophic fibers both alone and in groups. Peripheral nerves present with a fascicular pattern of mild nerve fiber loss with occasional small, thinly myelinated nerve fibers. Variable depletion of myelinated nerve fibers is observed in intramuscular nerve branches. In the spinal cord, there is severe loss of large ventral root myelinated axons with replacement by endoneurial connective tissue. These findings were not present in dorsal nerve roots. Segmental demyelination was not observed in dorsal or ventral roots. (He et al., 2005). [IT thanks DVM student Jacqualine Yue for suggested changes in April 2022]Control: Cats from at risk breeds used for breeding should be tested for the causative mutation. Affected cats should not be bred. Carriers should only be bred to tested cats demonstrated to be noncarriers.
Associated gene(s)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- Gene: Entrez Gene ID 3615802 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
- OMIA molecular-genetics note: The causative mutation is a ~140 kb deletion (omia.variant:649) removing exons 4-6 of <em>LIX1</em> and all except exon 1 of <em>LNPEP</em> (Fyfe et al., 2006).
Evidence (references)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- 2005. Inherited motor neuron disease in domestic cats: a model of spinal muscular atrophy. Pediatr Res — PubMed:PMID15635053 | DOI:10.1203/01.PDR.0000153625.46892.6F — OMIA Phene_Article / Article
- 2006. An approximately 140-kb deletion associated with feline spinal muscular atrophy implies an essential LIX1 function for motor neuron survival. Genome Res — PubMed:PMID16899656 | DOI:10.1101/gr.5268806 — OMIA Phene_Article / Article
- 2008. Candidate screening of the bovine and feline spinal muscular atrophy genes reveals no evidence for involvement in human motor neuron disorders. Neuromuscular Disorders — PubMed:PMID18395445 | DOI:10.1016/j.nmd.2008.03.003 — OMIA Phene_Article / Article
- 2011. Lix1 knockout mouse does not exhibit spinal muscular atrophy phenotype. J Hered — PubMed:PMID21846745 | DOI:10.1093/jhered/esr031 — OMIA Phene_Article / Article
- 2005. Feline spinal muscular atrophy. Pediatr Res — PubMed:PMID15635052 | DOI:10.1203/01.PDR.0000153671.11277.83 — OMIA Phene_Article / Article
- 2011. Failure of lower motor neuron radial outgrowth precedes retrograde degeneration in a feline model of SMA. J Comp Neurol — PubMed:PMID22120001 | DOI:10.1002/cne.23010 — OMIA Phene_Article / Article
- 2011. Propagation of multiple cat hereditary disease models following assisted reproduction with frozen semen and embryos. Reproduction, Fertility and Development — OMIA Phene_Article / Article
- 2022. Genetic epidemiology of blood type, disease and trait variants, and genome-wide genetic diversity in over 11,000 domestic cats. PLoS Genet — PubMed:PMID35709088 | DOI:10.1371/journal.pgen.1009804 — OMIA Phene_Article / Article
Comparative medicine (human OMIM)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- OMIM:610466 (type: gene) — OMIA Group_OMIM (via OMIA_ID)
verification_derived: method: derived_from_dataset source: "OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM" note: "Structured fields (gene, variant rsID/protein change, PubMed/DOI references, OMIM cross-link) extracted from OMIA dump and presented with first-hand values; not verbatim prose."