title: A novel 4p16.3 microduplication distal to WHSC1 and WHSC2 characterized by oligonucleotide array with new phenotypic features.
abstract: Larger imbalances on chromosome 4p in the form of deletions associated with Wolf-Hirschhorn syndrome (WHS) and duplications of chromosome 4p have a defined clinical phenotype. The critical region for both these clinical disorders has been narrowed based on the genotype-phenotype correlations. However, cryptic rearrangements in this region have been reported infrequently. We report on a male patient with a microduplication of chromosome 4p, who presents with findings of macrocephaly, irregular iris pigmentation-heterochromia, and preserved linear growth in addition to overlapping features of trisomy 4p such as seizures, delayed psychomotor development, and dysmorphic features including prominent glabella, low-set ears, and short neck. Using a high-density oligonucleotide microarray, we have identified a novel submicroscopic duplication involving dosage sensitive genes TACC3, FGFR3, and LETM1. The microduplication did not involve WHSC1 and WHSC2 which are considered in the critical region for WHS and trisomy 4p. This patient's presentation and genomic findings help further delineate clinical significance of re-arrangements in the 4p16 region without the involvement of WHS critical region.
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Cyr
authors.forename: Manjunath
authors.initials: M
authors.lastname: Nimmakayalu
authors.forename: Susannah Q
authors.initials: SQ
authors.lastname: Longmuir
authors.forename: Shivanand R
authors.initials: SR
authors.lastname: Patil
authors.forename: Kim M
authors.initials: KM
authors.lastname: Keppler-Noreuil
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Shchelochkov
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D002869:Chromosome Aberrations; D058674:Chromosome Duplication; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D056726:Genetic Association Studies; D005838:Genotype; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics; D006801:Humans; D007223:Infant; D007499:Iris Diseases / Q000235:genetics; D008297:Male; D058627:Megalencephaly / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010859:Pigmentation Disorders / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D035602:Transcriptional Elongation Factors / Q000235:genetics; D054877:Wolf-Hirschhorn Syndrome / Q000235:genetics
chemical_list: C120899:NELFA protein, human; D012097:Repressor Proteins; D035602:Transcriptional Elongation Factors; D011495:Histone-Lysine N-Methyltransferase; C419586:NSD2 protein, human