Table 1.

Genetic, clinical and myopathological features of EBS-MD patients

Pat.	PLEC-Mutations and their effects on plectin protein expession	Clinical phenotype	Myopathological findings
1, m	▪ compound heterozygous ▪ exon 19: c.2264_2266delTCT/p.(Phe755del) (in-frame deletion) ▪ exon 24: c.3119_3120delAA/p.(Lys1040Argfs*139) (premature termination codon) ➢ no detectable plectin protein expression	▪ EBS: since birth ▪ myopathy: generalized; predominantly affecting shoulder-girdle and lower leg muscles ▪ dilated cardiomyopathy; ventricular arrhythmias	▪ LM: myopathic pattern; fibers with rubbed-out lesions; desmin-protein aggregates ▪ EM: degenerating myofibrills; autophagic vacuoles (triceps muscle; age at biopsy: 33 years)
2, f [17]	▪ homozygous ▪ exon 32: c.13459_13474dup/p.(Glu4492Glyfs*48) (premature termination codon) ➢ reduced plectin protein expression (full-length and rodless)	▪ EBS: since birth ▪ myopathy: generalized; predominantly affecting proximal muscle groups; facial weakness; marked bilateral ptosis; incomplete external ophthalmoplegia, ▪ mild left ventricular cardiac hypertrophy ▪ bilateral cataracts ▪ brain atrophy with hydrocephalus ex vacuo	▪ LM: myopathic pattern; rimmed-vacuoles; fibers with rubbed-out lesions; desmin-protein aggregates ▪ EM: degenerating myofibrils; cytoplasmic bodies; abnormally shaped mitochondria with paracristalline inclusions; desmin-positive filaments and sub-sarcolemmal protein aggregates (quadriceps muscle; age at biopsy: 25 years)
3, f [11]	▪ homozygous ▪ exon 31: c.5018_5036del/p.(Leu1673Argfs*64) (premature termination codon) ➢ expression of rodless plectin protein only	▪ EBS: since birth ▪ myopathy: mild neck flexion, shoulder abduction, elbow flexion and hand muscle weakness ▪ inspiratory stridor in the postnatal period due to moderate supraglottic obstruction caused by interarytenoid scarring	▪ LM: myopathic pattern; fibers with rubbed-out lesions; COX-negative fibers; desmin-protein aggregates ▪ EM: not performed (biceps muscle; age at biopsy 24 years)

Plectin mutations are assigned to a common reference sequence, GenBank accession number NM_000445.3. Pat. indicates patient; m, male; f, female; yrs, years; LM, light microscopy; EM, electron microscopy