An Interesting and Unique Case of 8p23.3p23.1 Deletion and 8p23.1p11.1 Interstitial Duplication Syndrome

A novel genotype-phenotype between persistent-cloaca-related VACTERL and mutations of 8p23 and 12q23.1

The mechanism underlying anorectal malformations (ARMs)-related VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, and renal and limb abnormalities) remains unclear. Copy number variation (CNV) contributed to VACTERL pathogenicity. Here, we report a novel CNV in 8p23 and 12q23.1 identified in a case of ARMs-related VACTERL association. This 12-year-old girl presented a cloaca (urethra, vagina, and rectum opening together and sharing a single tube length), an isolated kidney, and a perpetuation of the left superior vena cava at birth. Her intelligence, growth, and development were slightly lower than those of normal children of the same age. Array comparative genomic hybridization revealed a 9.6-Mb deletion in 8p23.1-23.3 and a 0.52-Mb duplication in 12q23.1 in her genome. Furthermore, we reviewed the cases involving CNVs in patients with VACTERL, 8p23 deletion, and 12q23.1 duplication, and our case was the first displaying ARMs-related VACTERL association with CNV in 8p23 and 12q23.1. These findings enriched our understanding between VACTERL association and the mutations of 8p23 deletion and 12q23.1 duplication. IMPACT: This is a novel case of a Chinese girl with anorectal malformations (ARMs)-related VACTERL with an 8p23.1-23.3 deletion and 12q23.1 duplication. Cloaca malformation is presented with novel copy number variation in 8p23.1-23.3 deletion and 12q23.1 duplication.

Genetic and epigenetic mechanisms in the development of congenital heart diseases

Congenital heart disease (CHD) is the most common of congenital cardiovascular malformations associated with birth defects, and it results in significant morbidity and mortality worldwide. The classification of CHD is still elusive owing to the complex pathogenesis of CHD. Advances in molecular medicine have revealed the genetic basis of some heart anomalies. Genes associated with CHD might be modulated by various epigenetic factors. Thus, the genetic and epigenetic factors are gradually accepted as important triggers in the pathogenesis of CHD. However, few literatures have comprehensively elaborated the genetic and epigenetic mechanisms of CHD. This review focuses on the etiology of CHD from genetics and epigenetics to discuss the role of these factors in the development of CHD. The interactions between genetic and epigenetic in the pathogenesis of CHD are also elaborated. Chromosome abnormalities and gene mutations in genetics, and DNA methylations, histone modifications and on-coding RNAs in epigenetics are summarized in detail. We hope the summative knowledge of these etiologies may be useful for improved diagnosis and further elucidation of CHD so that morbidity and mortality of children with CHD can be reduced in the near future.

Structural abnormalities of chromosome 8 and fetoplacental discrepancy: A second case report and review of fetal phenotype of 8p inverted duplication deletion syndrome

We described a new second case of fetoplacental discrepancy involving first trimester prenatal detection of mosaic isochromosome i (8) (q10). A 32-year-old woman underwent chorionic villous sampling because of increased fetal nuchal translucency. Analysis of direct chromosome preparations was performed by R-banding and FISH using subtelomeric, centromeric and whole chromosome painting probes for chromosome 8 showing the presence of an isochromosome 8q with a complex, female mosaic karyotype: mos 46,XX,i (8) (q10)[13]/46,XX,del (8) (p23)[10]. Cytogenetic analysis of cultured CVS showed an interstitial duplication with concomitant terminal deletion of the short arm of chromosome 8: 46,XX,der (8)del (8) (p23)dup (8) (p?)[18]. Array-CGH analysis from cultured trophoblasts and fetal tissues revealed a 6.69 Mb terminal deletion in 8p23.3p23.1 associated with a 31.49 Mb duplication in 8p23.1p11.1. FISH analysis confirmed the 8p inverted duplication deletion syndrome. Moreover, polymorphic DNA marker analysis demonstrated that the derivative chromosome 8 was of maternal origin. FISH analysis of cultured peripheral blood lymphocytes showed that the mother also carried a cryptic paracentric inversion inv (8) (p23). Our report contributes to expand the fetal phenotype of 8p inverted duplication deletion syndrome and also provides further insight into the underlying mechanism of this rare genomic disorder.

Deciphering the Invdupdel(8p) Genotype-Phenotype Correlation: Our Opinion

The 8p inverted duplication/deletion is a rare chromosomal rearrangement clinically featuring neurodevelopmental delay, mild to severe cognitive impairment, heart congenital defects and brain abnormalities. Patients affected also present typical facial dysmorphisms and skeletal malformations, and it is thought that the composite clinical picture may fall into the chromosomal rearrangement architecture. With the major aim of better framing its related clinical and diagnostic paths, we describe a patient carrying a de novo invdupde[8p] whose clinical features have not been described so far. Hence, through an extensive genotype-phenotype correlation analysis and by reviewing the dedicated scientific literature, we compared our patient's features with those reported in other patients, which allows us to place our proband's expressiveness in an intermediate area, widening the scope of the already known invdupde[8p] genotype-phenotype relationship.