title: Clinical features associated with copy number variations of the 14q32 imprinted gene cluster.
abstract: Uniparental disomy (UPD) for imprinted chromosomes can cause abnormal phenotypes due to absent or overexpression of imprinted genes. UPD(14)pat causes a unique constellation of features including thoracic skeletal anomalies, polyhydramnios, placentomegaly, and limited survival; its hypothesized cause is overexpression of paternally expressed RTL1, due to absent regulatory effects of maternally expressed RTL1as. UPD(14)mat causes a milder condition with hypotonia, growth failure, and precocious puberty; its hypothesized cause is absence of paternally expressed DLK1. To more clearly establish how gains and losses of imprinted genes can cause disease, we report six individuals with copy number variations of the imprinted 14q32 region identified through clinical microarray-based comparative genomic hybridization. Three individuals presented with UPD(14)mat-like phenotypes (Temple syndrome) and had apparently de novo deletions spanning the imprinted region, including DLK1. One of these deletions was shown to be on the paternal chromosome. Two individuals with UPD(14)pat-like phenotypes had 122-154kb deletions on their maternal chromosomes that included RTL1as but not the differentially methylated regions that regulate imprinted gene expression, providing further support for RTL1 overexpression as a cause for the UPD(14)pat phenotype. The sixth individual is tetrasomic for a 1.7Mb segment, including the imprinted region, and presents with intellectual disability and seizures but lacks significant phenotypic overlap with either UPD(14) syndrome. Therefore, the 14q32 imprinted region is dosage sensitive, with deletions of different critical regions causing UPD(14)mat- and UPD(14)pat-like phenotypes, while copy gains are likely insufficient to recapitulate these phenotypes.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Rosenfeld
authors.forename: Joyce E
authors.initials: JE
authors.lastname: Fox
authors.forename: Maria
authors.initials: M
authors.lastname: Descartes
authors.forename: Fallon
authors.initials: F
authors.lastname: Brewer
authors.forename: Tracy
authors.initials: T
authors.lastname: Stroud
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Gorski
authors.forename: Sheila J
authors.initials: SJ
authors.lastname: Upton
authors.forename: John B
authors.initials: JB
authors.lastname: Moeschler
authors.forename: Berrin
authors.initials: B
authors.lastname: Monteleone
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Neill
authors.forename: Allen N
authors.initials: AN
authors.lastname: Lamb
authors.forename: Blake C
authors.initials: BC
authors.lastname: Ballif
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Shaffer
authors.forename: J Britt
authors.initials: JB
authors.lastname: Ravnan
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D025063:Chromosome Disorders / Q000175:diagnosis / Q000235:genetics; D058674:Chromosome Duplication; D002883:Chromosomes, Human, Pair 14; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D019066:Facies; D005260:Female; D056726:Genetic Association Studies; D056426:Genetic Loci; D018392:Genomic Imprinting; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D005810:Multigene Family; D010641:Phenotype; D024182:Uniparental Disomy; D055815:Young Adult