Single gene disorder Mendelian traits caused by mutant alleles Exhibit obvious and charactetrisic pedigree pattern Autosomal versus sex-linked Dominant versus recessive(versus co dominant ( Black and white=grey Autosomal Dominant Inheritance Autosomal Recessive Inheritance (One Parent Affected) (Both Parents Carriers Affected Father Mother Carrier Father Carrier Mother D d dd Dd dd dd Rr R Affected Normal Affected Normal Son DaughterDaughter Son Normal Carrier Affected (25%)(25%)(25%)(25%) (25%) (50%) (25%) Occurrence of one disease rare( less than 1/500) But many different kinds of genetic disorder( 13000-20000)Single gene disorder Mendelian traits caused by mutant alleles Exhibit obvious and charactetrisic pedigree pattern Autosomal versus sex-linked Dominant versus recessive (versus co dominant (Black and white=grey) Occurrence of one disease rare ( less than 1/500) But many different kinds of genetic disorder ( 13000-20000 )