A case report of T-box 1 mutation causing phenotypic features of chromosome 22q11.2 deletion syndrome

Raad A Haddad,Jennifer A Wyckoff,Gregory A Clines

doi:10.1186/s40842-019-0087-6

Raad A Haddad, Jennifer A Wyckoff + Show 1 more

Open Access

https://doi.org/10.1186/s40842-019-0087-6

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Abstract

BackgroundThe heterozygous microdeletion of chromosome 22q11.2 results in a spectrum of disorders, including DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS), with phenotypic features that can include the classic triad of congenital heart disease (CHD), thymic aplasia and hypoparathyroidism. Such microdeletions are usually detectable by fluorescence in situ hybridization (FISH).Case presentationWe report a case of a twenty-three year-old female who presented with clinical features of chromosome 22q11.2 deletion syndrome including cardiac anomalies, hypoparathyroidism and dysmorphic facial features. FISH did not reveal a 22q11.2 microdeletion. Further genetic analysis showed T box-1 (TBX1) heterozygous mutation.ConclusionsThe TBX1 gene plays a significant role in the development of fourth pharyngeal arch structures. Mutations of TBX1, which is found at chromosome 22q11.21 can be responsible for the development of syndromes classically associated with chromosome 22q11.2 deletions. This case emphasizes that the TBX1 gene, among other genes, can be responsible for the developmental anomalies seen in these syndromes.

Highlights

The heterozygous microdeletion of chromosome 22q11.2 results in a spectrum of disorders, including DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS), with phenotypic features that can include the classic triad of congenital heart disease (CHD), thymic aplasia and hypoparathyroidism
DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), and various other syndromes have been described in association with the deletion involving human chromosome 22q11.2 [1]
We report a case of a twenty-three year-old female who presented with phenotypic features of 22q11.2 deletion and was found to have heterozygous mutation of the T box-1 (TBX1) gene

Summary

Conclusions

The TBX1 gene plays a significant role in the development of fourth pharyngeal arch structures. Mutations of TBX1, which is found at chromosome 22q11.21 can be responsible for the development of syndromes classically associated with chromosome 22q11.2 deletions. This case emphasizes that the TBX1 gene, among other genes, can be responsible for the developmental anomalies seen in these syndromes

Background

Discussion and conclusions