The positional candidate may belong to a certain functional group of genes (e.g. various sodium channel proteins in Generalised Epilepsy with Febrile Seizures (GEFS+) [16]), biochemical pathways (e.g. O-glycolysation defects in congenital myopathies; FCMD, POMGNT1, POMT1, POMT2, LARGE[17]) or sub-cellular organelles (e.g. impaired mitochondrial protein synthesis in mutations of mitochondrial elongation factors EFG1 and TSFZ[18], [19]). The gene discussed is GFM1; the disease is congenital myopathy with cores.