Clinical features associated with copy number variations of the 14q32 imprinted gene cluster.

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.

Investigation of NRXN1 deletions: clinical and molecular characterization.

Deletions at 2p16.3 involving exons of NRXN1 are associated with susceptibility for autism and schizophrenia, and similar deletions have been identified in individuals with developmental delay and dysmorphic features. We have identified 34 probands with exonic NRXN1 deletions following referral for clinical microarray-based comparative genomic hybridization.

High-resolution array CGH defines critical regions and candidate genes for microcephaly, abnormalities of the corpus callosum, and seizure phenotypes in patients with microdeletions of 1q43q44.

Microdeletions of 1q43q44 result in a recognizable clinical disorder characterized by moderate to severe intellectual disability (ID) with limited or no expressive speech, characteristic facial features, hand and foot anomalies, microcephaly (MIC), abnormalities (agenesis/hypogenesis) of the corpus callosum (ACC), and seizures (SZR). Critical regions have been proposed for some of the more prominent features of this disorder such as MIC and ACC, yet conflicting data have prevented precise determination of the causative genes. In this study, the largest of pure interstitial and terminal deletions of 1q43q44 to date, we characterized 22 individuals by high-resolution oligonucleotide microarray-based comparative genomic hybridization.

Impact of genotype-first diagnosis: the detection of microdeletion and microduplication syndromes with cancer predisposition by aCGH.

Background: The use of microarray-based comparative genomic hybridization has allowed the genetic diagnosis of some conditions before their full clinical presentation. This "genotype-first" diagnosis has the most clinical implications for genomic alterations that confer an elevated risk of cancer. In these cases, diagnosis before the manifestation of the patient's full phenotype dramatically impacts genetic counseling, clinical management, and eventual prognosis and survivability.