Categories: Muscle phene

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 256030 (trait) , 161650 (gene)

Links to MONDO diseases:

• MONDO:0009725: nemaline myopathy 2

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2016

History: Evans et al. (2016) described "a novel NM [nemaline myopathy] in a family of American bulldogs"

Molecular basis: Evans et al. (2016) reported a likely causal variant, namely "a nonsense mutation in NEB (g.52734272 C>A, S8042X) . . . The pathogenic variant was absent from 120 dogs of 24 other breeds and 100 unrelated ABDs, suggesting that it occurred recently and may be private to the family".

Clinical features: Evans et al. (2016): "Affected dogs could independently ambulate, had generalized atrophy, and the myopathy was relatively non-progressive (Supplemental video). Atrophy of the cervical and dorsal thoracic limb muscles was noted with bilateral hypertrophy of the triceps muscles. Serum creatine kinase (CK) activities were mildly elevated. Electromyography (EMG) revealed spontaneous electrical activity, consisting mainly of fibrillation potentials, within the proximal appendicular muscles of the thoracic limbs and the cervical paraspinal musculature. Motor nerve conduction velocity (MNCV) testing showed a mild decrease in the latency of the tibial and ulnar nerves. Respiratory difficulties were not present."

Breed: American Bulldog.
Breeds in which the phene has been documented. For breeds in which a likely causal variant has been documented, see the variant table below

Associated gene: