Phenotypes
Muscle weakness, CACNA1S-related — Recumbency
Al-Khudhair et al. (2024) report a variant in the CACNA1S gene (rs3423414874) as likely causal variant for this condition.
Muscular hypertrophy (double muscling) — Double muscling; “culón”; horse rump
The double-muscle trait in cattle is characterised by an increase in muscle mass of approx 20%, resulting in substantially higher meat yield, a higher proportion of expensive cuts of meat, and lean and very tender meat, for which a substantial premium is paid. The trait is autosomal recessive, and the locus has been given the symbol mh. It occurs at such a high frequency in Piedmontese and Belgian Blue cattle that it is characteristic of these...
Myasthenia
No summary available.
Myasthenic syndrome, congenital, CHRNE-related
Redundant - information about congenital myasthenic syndrome in Brahman cattle was moved to OMIA:000685-9915 : Myasthenic syndrome, congenital, CHRNE-related in Bos indicus [08/10/2023]
Myeloencephalopathy, progressive degenerative, PNPLA8-related — Weaver syndrome; Haplotype BHW; bovine degenerative progressive myeloencephalopathy
Kunz et al. (2016) reported a likely causal mutation as "a missense mutation (p.S568N, c.G1703A; [Chr4: 49,878,773 bp, rs800397662]) in the PNPLA8 gene that encodes patatin-like phospholipase domain containing 8".
Myoclonus epilepsy of Lafora
No summary available.
Myopathy of the diaphragmatic muscles
From a BAC contig encompassing the candidate region of the bovine MHC (see Mapping section above), Sugimoto at al. (2003) determined that this disorder in Holstein-Friesian cattle is due to the deletion of one of two HSP70 (heat-shock protein) genes in the bovine major histocompatibility complex.
Myositis ossificans
No summary available.
Myotonia
No summary available.
Nasolacrimal duct obstruction — Also known as nasolacrimal duct fistula or lacrimal fistula.
Previously listed in OMIA as OMIA:001693-9913 : Lacrimal fistula in Bos taurus (taurine cattle) [06.05.2024]
Necrotising encephalopathy, subacute, of Leigh
Characterised by abnormal mitochondria, this disorder could be due to mutation(s) in mitochondrial DNA.
Neoplasm, generic
No summary available.
Neospora caninum infection, susceptibility/resistance to
No summary available.
Neuroaxonal dystrophy, generic
No summary available.
Neurocristopathy
Bourneuf et al. (2017): a de novo likely causal variant is the frameshift variant p.K594AfsX29