Case Study: Patient with 7p14–P21 Deletion Spanning the TWIST Gene and the HOXA Gene Cluster
Nadia Mebrouk *
Medicine and Neonatal Resuscitation Service, Reference National Center for Neonatology and Nutrition of Rabat, Children's Hospital Rabat, Morocco.
Amina Barkat
Medicine and Neonatal Resuscitation Service, Reference National Center for Neonatology and Nutrition of Rabat, Children's Hospital Rabat, Morocco.
*Author to whom correspondence should be addressed.
Abstract
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.
Keywords: Contiguous gene syndrome, hand-foot-uterus syndrome, HOXA, Saethre-chotzen syndrome, TWIST.