Prenatal detection of a 3q29 microdeletion in a fetus with ventricular septum defect

Abstract

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.

3q29 microdeletion syndrome associated with developmental delay and pulmonary stenosis: a case report

“…9 Besides, in a recently published case report, a fetus with VSD was diagnosed with 3q29 deletion prenatally and after genetic counseling, the family decided to terminate the pregnancy. 10 3q29 microdeletion syndrome provides an important opportunity to investigate genes related to complex neuropsychiatric diseases. 3q29 microdeletion syndrome was first described in six patients with GDD or intellectual disability (ID) ranging from mild to moderate in cases.…”

“…Likewise, biallelic mutations in TFRC (OMIM 190010) gene is related to autosomal recessively inherited immunodeficiency 46 (OMIM 616740), and this gene is not encompassed in our patient's deletion. 10 The aCGH method is used as a first-line clinical diagnostic genetic test for further investigation in unexplained GDD/ID cases despite detailed evaluations of history, hearing and vision, and EEG recordings (in suspicious cases). Furthermore, in cases where cardiac defects are seen in addition to dysmorphic symptoms, neuropsychiatric or neurodevelopmental problems, gastrointestinal or musculoskeletal abnormalities, it is important to test for CNVs.…”