@entity6038 are 2 clinically distinct disorders associated with @entity156 and @entity1032 . They are only discussed together because they share a similar and uncommon genetic basis: they involve genes that are located in the same region in the genome and are characterized by genetic imprinting. This normal process has contributed to these 2 complex and severe conditions through inactivation of 1 copy of the genes relevant to each disorder: the maternally derived copy of genes for @entity6038 in proximal 15q are normally silent, and a paternally derived copy of 1 gene for @entity5427 in 15q is normally silent. For both disorders, when the normally active copy of the gene or genes is missing, abnormality results. Since the genes for these 2 disorders are located very close together, and since the center involved in inactivating the genes involved in imprinting may be the same, both these disorders usually result from the same chromosomal deletion; @entity74 results depends on the parent of origin of the chromosome 15 that becomes deleted. Both @entity6038 and @entity5427 can also occur as a result of having both members of the chromosome 15 pair derived from 1 parent, a condition known as @entity8882 . Both can also result from a structural abnormality of the imprinting center, known as an imprinting mutation. In addition, @entity5427 can be caused by a mutation in the gene that causes it; a comparable cause is not present in @entity6038 since it results from abnormality in more than 1 gene. Finally, despite the complexity of possible causes, all but the single gene mutation of the @entity5427 gene can be detected through methylation-sensitive DNA probes, since DNA methylation is the process by which the genes for these 2 disorders are imprinted. This unusual property of specific areas of the DNA holds promise for future treatment of these and other disorders related to imprinting through reversal of the imprinting process.

XXXX . Disorders of genomic imprinting.

@entity5427 :: ('MESH:D017204', 'Disease') :: ['Angelman syndrome'] @entity1032 :: ('MESH:D008607', 'Disease') :: ['mental retardation'] @entity156 :: ('MESH:D000015', 'Disease') :: ['multiple anomalies'] @entity74 :: ('MESH:D030342', 'Disease') :: ['which disorder'] @entity6038 :: ('MESH:D011218', 'Disease') :: ['Prader-Willi and Angelman syndromes', 'Prader-Willi', 'Prader-Willi syndrome'] @entity8882 :: ('MESH:D024182', 'Disease') :: ['uniparental disomy']
@entity6038 :: (MESH:D011218,Disease) :: ['Prader-Willi and Angelman syndromes']
