A LOVEABLE 8-year-old boy has a form of dwarfism so rare he is believed to be one of only 28 cases in the world. Three-foot-tall Landen Johnson, from Lincolnton, North Carolina, has primordial dwarfism, one of the rarest forms of dwarfism in the world, with experts estimating there are less than 100 cases worldwide. But Landen’s specific form of primordial dwarfism, DNA Ligase four deficiency or Ligase 4 deficiency, which also affects the immune system, makes him even rarer: his family say they know of only 28 other cases worldwide. Five months after having a bone marrow transplant Landen still has to go to hospital three times a week, can barely go outside and has to take multiple medications – but Landen’s spirit remains unbreakable.