<prompt> All of the following constitute familial cancer syndrome except -Xeroderma-pigmentosumRetinoblastomaNeurofibromatosisMEN-I  <response>: All are familial cancer syndromes.Xeroderma-pigmentosa is autosomal recessive, defective DNA repair syndrome.Other three are autosomal dominant inherited cancer syndrome.Amongst the given options best answer is a i.e. xeroderma pigmentosa because autosomal dominant inherited cancer syndromes are the most common type of genetically predisposed cancer. 