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Introduction: While several literature reports have been published about patients with microdeletions within chromosome 7p, only a small fraction of those reports is specific to deletions that encompass the TWIST gene and HOXA gene cluster. The large-span deletions within this cluster result in haploinsufficiency of six genes known to have a role in different autosomal dominant genetic disorders: TWIST1, GSDME (DFNA5), CYCS, HOXA11, HOXA13, and GARS. Deletion of TWIST1 gene on 7p21 and deletion of HOXA cluster on 7pl5.2 lead to Saethre-Chotzen syndrome and to hand-foot-genital syndrome, respectively.
Objectives: Our patient presented with a phenotype combining Saethre-Chotzen syndrome (SCS) and hand-foot-genital syndrome (HFS), which is similar to previously reported cases with a deletion spanning 7p21– p14.3. The objective of our report is to correlate the clinical observations with the patient’s genetic test result, namely 46,XY,del(7)(p14p21).
Patient and Methods: We describe a patient who had manifestations of SCS and HFU, caused by an interstitial deletion of chromosome 7p21–p14 detected by RHG band.
Results and Conclusion: We therefore confirm previous reports that microdeletions of 7p spanning the TWIST gene and HOXA gene cluster lead to a clinically recognizable ‘haploinsufficiency syndrome’. All of the features of this patient could be accounted for by combined effect of the deletion of the TWIST and HOXA cluster.
Devriendt K, Jaeken J, Matthijs G, Van Esch H, Debeer P, et al. Haploinsufficiency of the HOXA gene cluster, in a patient with hand- foot-genital syndrome, velopharyngeal in-sufficiency and persistent patent ductus botalli. Am J Hum Genet. 1999;65:249–251.
Gallagher ER, Ratisoontorn C, Cunningham ML. Saethre-Chotzen Syndrome. 2003 May 16 [Updated 2019 Jan 24]. In: Adam MP, Ardinger HH, Pagon RA, et al. editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020.
Kosaki R, Higuchi M, Mitsui N, Matsushima K, Ohashi H, Kosaki K. Deletion involving the TWIST locus and the HOXA cluster: A contiguous gene syndrome on 7p? Congenit Anom (Kyoto). 2005;45:35–38.
Chotai KA, Brueton LA, van Herwerden L, Garrett C, Hinkel GK, et al. Six cases of 7p deletion: Clinical, cytogenetic, and molecular studies. Am J Med Genet. 1994;51:270–276.
Duno M, Hove H, Kirchhoff M, Devriendt K, Schwartz M. Mapping genomic deletions down to the base: A quantitative copy number scanning approach used to characterize and clone the breakpoints of a recurrent 7p14.2p15.3 deletion. Hum Genet. 2004;115:459–467.