A Pure 2-Mb 3q26.2 Duplication Proximal to the Critical Region of 3q Duplication Syndrome.

Partial duplication of chromosome 3q - dup(3q) - is a recognizable syndrome with dysmorphic facial features, microcephaly, digital anomalies, and genitourinary and cardiac defects, as well as growth retardation and developmental delay. Most cases of dup(3q) result from unbalanced translocations or inversions and are accompanied by additional chromosomal imbalances. Pure dup(3q) is rare, and only 31 cases have been reported so far. We report a new case of a girl with a pure 2-Mb duplication at 3q26.2 not encompassing the known critical region 3q26.3q27. After an extensive review, to the best of our knowledge, the case herein presented harbors the shortest 3q duplication of this region. The clinical phenotype of this patient resembles previously reported cases of pure dup(3q) syndrome, including intellectual disability, synophrys, a wide nasal bridge, dysmorphic ears, clinodactyly, and cardiac defects. We suggest that the 3q26.2 duplication is a candidate copy number alteration explaining our patient's clinical phenotype.

ADULT Phenotype and rs16864880 in the TP63 Gene: Two New Cases and Review of the Literature.

The TP63 gene has been described in 5 overlapping limb malformation disorders, including a rare autosomal dominant ectodermal disorder named acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome. This article describes 2 patients with ectrodactyly and variable features related to ectodermal dysplasia/ADULT syndrome, and the polymorphism rs16864880 in the TP63 gene, which was not present in their parents. The role of this variant in the genesis of this condition is discussed, based upon a review of 40 cases. The results suggested that rs16864880 may not be directly related to ADULT syndrome. However, it is not possible to exclude its participation in gene interactions in the limb development pathway.

A New Case of the Rare 10q22.3q23.2 Microdeletion Flanked by Low-Copy Repeats 3/4.

Deletions in the 10q22.3q23.2 region are rare and mediated by 2 low-copy repeats (LCRs 3 and 4). These deletions have already been recognized as the 10q22q23 deletion syndrome. The phenotype associated with this condition is rather uncharacteristic, and most common features are craniofacial dysmorphisms and developmental delay. We describe a boy with craniofacial dysmorphic features, developmental delay, tetralogy of Fallot, hand/foot abnormalities, and recurrent respiratory tract infections. Chromosomal microarray analysis disclosed a 7.8-Mb microdeletion at 10q22.3q23.2, flanked by LCRs 3/4, and an additional 16q12.1 microdeletion of 189 kb. This article reviews the clinical signs of reported cases with similar deletions and compares them with our patient, contributing to a better understanding of genotype-phenotype correlation.