Five patients with a chromosome 1q21.1 triplication show macrocephaly, increased weight and facial similarities.

Recurrent rearrangements of chromosome 1q21.1 that occur as a consequence of non-allelic homologous recombination (NAHR) show considerable variability in phenotypic expression and penetrance. Chromosome 1q21.

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.

Phenotypic heterogeneity of genomic disorders and rare copy-number variants.

Background: Some copy-number variants are associated with genomic disorders with extreme phenotypic heterogeneity. The cause of this variation is unknown, which presents challenges in genetic diagnosis, counseling, and management.

Methods: We analyzed the genomes of 2312 children known to carry a copy-number variant associated with intellectual disability and congenital abnormalities, using array comparative genomic hybridization.