<i>De novo</i> duplication 3q in an infant with a vascular ring and features overlapping Cornelia de Lange phenotype

Abstract

Partial duplication of chromosome 3q is a recognizable syndrome with characteristic facial features, microcephaly, digital anomalies, genitourinary and cardiac defects as well as growth retardation and developmental delays. While there is clinical overlap with the unrelated Cornelia de Lange syndrome (CDLS), there are distinguishing features and molecular etiologies. Most cases of 3q duplication appear to be the result of an unbalanced translocation or inversion and therefore accompanied by additional cytogenetic anomalies. Consequently, pure duplications of 3q are very rare; we are aware of only 12 such cases that have been reported previously. Here, we present a new case of pure, partial 3q duplication in a 3-month-old female who displayed a number of clinical signs consistent with previously reported phenotypes and the additional novel finding of a vascular ring.

Genotype Phenotype Correlation of A Case Having Chromosome 3 Imbalance

“…Most cases with 3q duplication appear to be the result of an unbalanced translocation or inversion resulting in an associated deletion of another chromosomal segment, as in our patient (2). After pairing in a pericentric inversion generates four products: Chromosome with normal gene order, chromosome with inverted gene order and two duplication and/or deletion products in which one or more loci are duplicated or deleted, depending on where the crossover occurs (7).…”

“…It has been shown to emerge from the meiotic recombination of the 3rd chromosome containing a pericentric inversion in one of the parents (1). 3q+ syndrome that resembles Cornelia de Lange syndrome, represents one or many of the features such as mental retardation, developmental delay, seizures, prominent eyelashes, down-slanting palpebral fissures, epicanthal folds, broad nose, low-set malformed ears, prominent philtrum, downturned corners of the mouth and digital anomalies including brachydactyly and clinodactyly, hypertrichosis, cardiac, renal, and genital malformations in addition to pre-and postnatal growth retardation (2). More rarely reported features contain ocular anomalies, conductive hearing loss and hip dysplasia (3).…”