48, XXYY is a sex aneuploidy characterized by the presence of an extra X and Y chromosomes in males. Patients with this syndrome have medical problems, significant neurodevelopmental and psychological features, delayed eruption and agenesis of teeth, thin enamel, enamel hypoplasia or hypomineralization and taurodontism. This case report presents an important role of pediatric dentists in early diagnosis of chromosomal aneuploidy syndromes. A 10-year and 3-month old boy was referred to dental examination and treatment for non-cooperation. History and examination revealed developmental delay and learning difficulties, tall stature, obesity, facial dysmorphia, a high-arched palate, dental caries, peg-shaped lateral incisors, gingivitis, hypodontia, impaction of the upper permanent canine and hypertaurodontic first permanent molars. The findings of multiple hypertaurodontic permanent molars in a boy with psychological disorder were reason for promt genetic counseling. Chromosomal analysis confirmed the diagnosis of mosaic 48, XXYY/47,XXY syndrome with the predominant XXYY. • 48, XXYY syndrome is a rare sex chromosome aneuploidy characterized by the presence of an extra X and Y chromosome in males. • Mosaic 48, XXYY/47, XYY syndrome is commonly characterized by specific orofacial and dental features, developmental delays and learning difficulties. • The important role of dental practitioners, especially pediatric dentists, in early detection of clinical orofacial symptoms of rare syndromes. • Dental management of patients with 48, XXYY syndrome can be complicated by behavioral difficulties. • Genetic testing is indicated in cases of taurodontism.
Merglová et al. (2026) studied this question.