2q31 microdeletion syndrome with the velocardiofacial phenotype and review of the literature: a case report

Abstract

Background: The 2q31 deletion results in a distinct phenotype characterized by varying degrees of developmental delay, short stature, facial dysmorphism, and variable limb defects. Dysmorphic features include microcephaly, downslanting palpebral fissures, a long and flat philtrum, micrognathia, and dysplastic, low-set ears. To date, comparative genomic hybridization has identified this deletion in 38 patients. Consequently, additional patients with comprehensive clinical data are required to fully understand the spectrum of clinical manifestation associated with a deletion in the 2q31 cytoband.

Case presentation: We present the case of an 8-year-old female patient with clinical features of velocardiofacial syndrome, which include facial dysmorphism, congenital heart disease (persistent truncus arteriosus and ostium secundum-type atrial septal defect), and a seizure syndrome. Array comparative genomic hybridization revealed a non-continous deletion spanning cytobands 2q31.1-to 2q31.3, confirming a diagnosis of 2q31 microdeletion syndrome. The patient has undergone supportive therapies for swallowing and speech. Additionally, we provide a review of the literature on previous cases to give context.

Conclusion: In this report, we present the first documented case of a complex, discontinuous deletion spanning in the 2q31-2q32 regions. This case contributes to our understanding of the phenotypic and mutational spectrum observed in individuals with deletions in these cytobands. It underscores the significance of employing high-resolution techniques and comprenhensive analysis in diagnosing patients with complex phenotypes. Such approaches are crucial for differentiating this condition from more common microdeletion syndromes, such as the 22q11 deletion syndrome.

Keywords: 2q31-q32 microdeletion; Array CGH; Facial dysmorphism; Velocardiofacial syndrome.

Fig. 1

A representation of the aCGH results, which include the first deleted region of approximately 7.89 Mb of DNA localized on 2q31.1-q31.2, and the second deleted region of approximately 5.23 Mb on the cytoband 2q32.1

Fig. 2

Map of the deletions, comprising at least the 2q31.1 region, of the cases found in the literature. The map was create using UCSC Genome Browser on Human (GRCh37/hg19) [20]. Genomic coordinates of the reported deletions were converted to the GRCh37/hg19 coordinates using the LiftOver tool of the UCSC. Black bar indicates the length of the deletion found. Delimited regions indicate some genes or clusters mentioned in the text. Patients from Dimitriv et al. [3] were not included as no genomic positions were reported. Panel A displays the genes reported in both the literature and our case study, whereas Panel B highlights the most relevant genes according to the literature review, including those occurring with higher frequency