<prompt> Classic human disorders related to genomic imprinting include all EXCEPTPrader-Willi syndromeAngelman syndromeBeckwith-Wiedemann syndromeDuchenne muscular dystrophy  <response>: D Duchenne muscular dystrophy Genomic imprinting refers to a genetic phenomenon whereby there is preferential expression of a gene from only one of the two parental alleles. This phenomenon of allele-specific expression results from allele-specific epigenetic modifications such as CpG dinucleotide methylation or histone methylation or histone acetylation. These modifications are referred to as epigenetic modifications also referred to as epigenetic marks. In non-imprinted regions of the chromosomes, the parental epigenetic marks are erased in the germ cells only to be newly established in a parental-specific manner. Classic human disorders related to genomic imprinting are Prader-Willi syndrome PWS, Angelman syndrome AS, Beckwith-Wiedemann syndrome BWS, Russell-Silver syndrome RSS, and Albright hereditary osteodystrophy. A characteristic feature of all of these diseases is that they do not exhibit normal Mendelian patterns of inheritance as well as showing parental origin effects. The normal role of imprinting seems to have evolved to fine-tune the growth and development of the fetus.SYNDROMES INVOLVING IMPRINTED GENESCHROMOSOMAL LOCATION Beckwith-Wiedemann syndrome, BWS11p15 Prader-Willi syndrome, PWS15q11.2-q12 Angelman syndrome, AS15q11.2-q12 Russell-Silver syndrome, RSS7p11-p13, 7q31-qter Transient neonatal diabetes mellitus, TNDM6q24 Albright hereditary osteodystrophy, McCune- Albright syndrome, PHP1b20q13 Familial nonchromaffin paraganglioma11q13 Maternal and paternal UPD14 syndromes14 In addition to the syndromes listed in the Table above several diseases that are the result of complex genetic involvement have been shown to exhibit parent-of-origin effects. These disorders include autism, Hirschsprung disease, Alzheimer disease, schizophrenia, bipolar affective disorder, and type 1 and type 2 diabetes. 