A novel proximal 3q29 chromosome microdeletion in a Chinese patient with Chiari malformation type II and Sprengel's deformity

Other Types of Glycosylation

O-Linked glycosylation such as O-fucose, O-glucose, and O-N-acetylglucosamine are considered to be unusual. As suggested by the high levels of evolutional conservation, these O-glycans are fundamentally important for life. In the last two decades, our understanding of the importance of these glycans has greatly advanced. In particular, identification of the glycosyltransferases responsible for the biosynthesis of these glycans has accelerated basic research on the functional significance and molecular mechanisms by which these O-glycans regulate protein functions as well as clinical research on human diseases due to changes in these types of O-glycosylation. Notably, Notch receptor signaling is modified with and regulated by these types of O-glycans. Here, we summarize the current view of the structures and the significance of these O-glycans mainly in the context of Notch signaling regulation and human diseases.

Prenatal detection of a 3q29 microdeletion in a fetus with ventricular septum defect: A case report and literature review

RATIONALE

Chromosomal 3q deletion is a recurrent genomic alternation, which is rarely reported in clinic.

PATIENT CONCERNS

A 27-year-old woman underwent amniocentesis for cytogenetic analysis and single nucleotide polymorphism (SNP) array analysis at 27 weeks of gestation, due to ventricular septum defect in prenatal ultrasound findings.

DIAGNOSES

G-banding analysis showed the karyotype of the fetus was normal and the couple also had normal karyotypes. However, SNP array detected a 1.71 Mb microdelection in 3q29, which was described as arr[hg19]3q29(194184392-195887205) × 1. There are 12 genes located in this locus.

INTERVENTIONS

The couple refused SNP array to testify the 3q29 microdeletion was inherited or de novo and they chose termination of pregnancy.

OUTCOMES

The deleted region in the fetus overlapped with part 3q29 microdeletion syndrome, which was characterized by learning disability, speech delay, mental deficiency, ocular abnormalities and craniofacial features. In addition, no similar/overlapping 3q29 microdeletion cases were reported according to the published literature and database.

LESSONS

For the chromosomal microscopic imbalances partially overlapping with the defined pathogenic syndrome, deleted/duplicated size, genetic materials and phenotypic diversity should be taken into consideration when genetic counseling is offered by the clinicians.