Diagnosis of 22q11.2 Deletion Syndrome in a Child With Congenital Heart Disease and Facial Dimorphism: A Case Report

Abstract

22q11.2 deletion syndrome is caused by a deletion in chromosome 22q11.2 and has more than 180 distinct phenotypes, however, no finding is pathognomonic or even mandatory. This syndrome can be diagnosed by fluorescence in situ hybridization. Thus, we report herein a patient from Manaus, Brazil who has congenital heart disease and facial dimorphism with the presence of 22q11.2 deletion in the N25 region. Male patient, 1 year old, son of non-consanguineous parents and without family history of genetic disease. The patient was hospitalized in the cardiac intensive care unit of the Francisca Mendes University Hospital for surgery. The patient was diagnosed with interventricular communication, low atrial implantation, hypertelorism and macroglossia. The FISH result revealed the presence of proximal deletion in the N25 region (22q11.2) in only one of the pair in chromosome 22. This finding revealed a diagnosis of 22q11.2 deletion syndrome, in other words, a hemizygotic deletion with haploinsufficiency of the CLTCL1 gene in this region. However, it is valid to say that the CLTCL1 gene is related to the clinical picture of the patient reported in this study. Cytogenomic analysis was essential for the etiological diagnosis and revealed 22q11.2 deletion in the N25 region, which resulted in 22q11.2 deletion syndrome. The importance of diagnosing this syndrome lies in the best therapeutic conduct, thus allowing a better quality of life to the patient and adequate genetic counseling. Other cytogenomic studies are essential in order to elucidate the size of the deletion and low copy repeats involved in this deletion.

Keywords

• Chromosome 22
• Region 22q11.2
• Fluorescence in situ hybridization
• Region N25.