Delineation of the breakpoints of pure duplication 3q due to a de novo duplication event using SOMA

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.

Rare de novo inversion-duplication case with pure 3qter duplication syndrome including an overlap of the dup(3q) critical region: A case report

We report here a very rare case of de novo inversion-duplication chromosomal abnormality with a pure 3qter duplication syndrome. Interestingly, the 3q duplication includes an overlap of the syndromes critical region. Although there have only been 9 cases of this syndrome reported in the past, our patient had more severe neurological abnormalities than anticipated. In this regard, we have gathered the 3q chromosomal duplication abnormalities known to cause pure 3q duplication syndrome to date as a reference for comparisons and we discuss the particulars of our case.

Comprehensive review of the duplication 3q syndrome and report of a patient with Currarino syndrome and de novo duplication 3q26.32-q27.2

Partial duplications of the long arm of chromosome 3, dup(3q), are a rare but well-described condition, sharing features of Cornelia de Lange syndrome. Around two thirds of cases are derived from unbalanced translocations, whereas pure dup(3q) have rarely been reported. Here, we provide an extensive review of the literature on dup(3q). This search revealed several patients with caudal malformations and anomalies, suggesting that caudal malformations or anomalies represent an inherent phenotypic feature of dup(3q). In this context, we report a patient with a pure de novo duplication 3q26.32-q27.2. The patient had the clinical diagnosis of Currarino syndrome (CS) (characterized by the triad of sacral anomalies, anorectal malformations and a presacral mass) and additional features, frequently detected in patients with a dup(3q). Mutations within the MNX1 gene were found to be causative in CS but no MNX1 mutation could be detected in our patient. Our comprehensive search for candidate genes located in the critical region of the duplication 3q syndrome, 3q26.3-q27, revealed a so far neglected phenotypic overlap of dup(3q) and the Pierpont syndrome, associated with a mutation of the TBL1XR1 gene on 3q26.32.

Clinical, Cytogenetic, and Biochemical Analyses of a Family with a t(3;13)(q26.2;p11.2): Further Delineation of 3q Duplication Syndrome

Chromosomal abnormalities that result in genomic imbalances are a major cause of congenital and developmental anomalies. Partial duplication of chromosome 3q syndrome is a well-described condition, and the phenotypic manifestations include a characteristic facies, microcephaly, hirsutism, synophrys, broad nasal bridge, congenital heart disease, genitourinary disorders, and mental retardation. Approximately 60%–75% of cases are derived from a balanced translocation. We describe a family with a pure typical partial trisomy 3q syndrome derived from a maternal balanced translocation t(3;13)(q26.2;p11.2). As the chromosomal rearrangement involves the short arm of an acrocentric chromosome, the phenotype corresponds to a pure trisomy 3q26.2-qter syndrome. There are 4 affected individuals and several carriers among three generations. The report of this family is relevant because there are few cases of pure duplication 3q syndrome reported, and the cases described here contribute to define the phenotype associated with the syndrome. Furthermore, we confirmed that the survival until adulthood is possible. This report also identified the presence of glycosaminoglycans in urine in this family, not related to the chromosomal abnormality or the phenotype.

3q26.31-q29 duplication and 9q34.3 microdeletion associated with omphalocele, ventricular septal defect, abnormal first-trimester maternal serum screening and increased nuchal translucency: prenatal diagnosis and aCGH characterization

We present prenatal diagnosis and array comparative genomic hybridization characterization of 3q26.31-q29 duplication and 9q34.3 microdeletion in a fetus with omphalocele, ventricular septal defect, increased nuchal translucency, abnormal first-trimester maternal screening and facial dysmorphism with distinct features of the 3q duplication syndrome and Kleefstra syndrome. The 26.61-Mb duplication of 3q26.31-q29 encompasses EPHB3, CLDN1 and CLDN16, and the 972-kb deletion of 9q34.3 encompasses EHMT1. We review the literature of partial trisomy 3q associated with omphalocele and discuss the genotype-phenotype correlation in this case.

A boy with partial trisomy of chromosome 3q24-q28 from paternal balanced insertion and multiple congenital anomalies

Although many patients with duplication 3q syndrome have been described reports on duplication derivatives from an insertion are rare in the previous literature. Here we describe the genotype and phenotype of a 32-month-old boy with a partial trisomy of 3q24-q28. We carefully mapped the aberration with SNP-array analysis, and found a duplication region of 44 Mb. By conventional cytogenetic techniques including fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY) analysis, the patient was found to have inherited a derivative chromosome 6 from his father, which was contained a direct insertion from 3q24-28. The main clinical features of the patient included severe mental retardation, postnatal developmental delay, ventricular septal defect (VSD), and craniofacial anomalies including cleft palate, frontal bossing, hypertelorism, and a broad nasal bridge. The symptoms partially overlap with previously reported patients with duplication in the same region. Prenatal diagnosis for the fetus of this family was performed based on the results of genetic tests and ultrasonic evaluation.