TTN and congenital myopathy with cores: Here we present the oldest documented patient with a congenital myopathy with rigid spine linked to a pathogenic novel homozygous variant c.36400A > T, p.Lys12134* in exon 170 of titin. Deep characterization and thorough functional studies showed a normal titin content and a conserved regenerative muscle capacity whilst an increased calcium sensitivity of force generation could be responsible for the highly contractural phenotype of our patient.