Williams-Beuren region duplication syndrome: case report

*Correspondence: [e-mail].

Abstract

Case Presentation: Patient, 14 years old, with prenatal diagnosis of pulmonary valve stenosis, submitted to pulmonary valvuloplasty after birth. She presented delayed cervical support, sitting, talking, and walking. She has difficulty keeping up with her class at school, does not know how to handle money, does not know how to look at the time on the clock, and does not leave the house alone. No parental consanguinity. On examination, normal hair implantation, broad forehead, small nose, prominent lips. Quite smiling, inattentive to the surroundings, bradykinetic and bradypsychic, performs simple commands, reads single words, cannot read a complete text. Referred to the genetics outpatient clinic and fluorescence in situ hybridization (FISH) was performed with the presence of microduplication 7q11.23.

Discussion: Microduplications are duplications too small to be detected by light microscopy using conventional cytogenetic methods. The phenotype of microduplication syndromes is usually less clear and less well defined than for the corresponding microdeletion syndrome. The specific genes on 7q11.23 are extremely sensitive to dosage changes that originate from deletions or duplications and that can influence the development of human language and visuospatial ability. The microdeletion present in Williams-Beuren syndrome (WBS) is evaluated using the FISH technique, which detects the hemizygosis of the elastin gene from blood analysis. It has a pattern of autosomal dominant inheritance, but most cases occur only in a single family member, being of de novo origin with a low risk of familial recurrence. Isolated supravalvular aortic stenosis is associated with intragenic mutations of the elastin gene, while WBS involves deletions of the elastin gene in its entirety; this suggests that supravalvular aortic stenosis, may be caused by quantitative or qualitative defects of the elastin gene. WBS is a rare neurodevelopmental disorder that affects connective tissue and the central nervous system. It presents typical facial dysmorphisms, congenital heart defects, growth deficits, and intellectual disability. It exhibits dissociation between verbal and nonverbal cognitive domains, with fluent speech and elevated empathetic and sociable behaviors standing out.

Final Comments: The phenotype of patients with WBS who have duplication or deletion is quite variable, and diagnosis is difficult during childhood, as this is a disease of progressive manifestation and features may not be present early in life.

Publication History

Article published online:
12 May 2025