Table 1 Severity of Hereditary myotonia affecting pigs, intensity of the main clinical signs, and the respective affected animals.

From: A large intragenic deletion in the CLCN1 gene causes Hereditary Myotonia in pigs

Clinical myotonia severity scale

Muscle hypertrophy

Muscle stiffness

Startle response/ recumbency

Animals

Absent

Absent

Absent

Absent

All control and heterozygous animals.

Mild

Present

+

Absent

O

Moderate

Present

++

+

A, B, C, D, and E

Intense

Present

++

++

P, U, and V