Longitudinal Behavioral and Metabolic Phenotype in a Child with a Distal Chromosome 15q21.3-22.2 Deletion

Authors

• Amber Conrad, University of LynchburgFollow

Specialty

Primary care

Advisor

Dr Sarah Bolander

Abstract

ABSTRACT

This case describes a 9-year-old boy with a rare interstitial chromosome 15q21.3-q22.2 deletion and provides longitudinal clinical insight in the progressive cognitive developmental, behavioral, and metabolic phenotype associated with this region.  A 5.0-Mb deletion involving 34 genes, including TCF12, a gene implicated in brain development and cognitive function, was identified using chromosomal microarray analysis.  The patient showed delay in developmental milestones, intellectual disability, attention-deficit/hyperactivity disorder, autism spectrum disorder, and a history of seizures.  An interesting feature of the clinical course was the transition from early feeding difficulties and failure to thrive to later hyperphagia, rapid weight gain, excess truncal adiposity, and pre-diabetic metabolic changes.  These findings suggest phenotype overlap with Prader-Willi syndrome, despite the deletion occurring distal to the 15q11.2-q13.1 critical region of the syndrome.  Behavioral dysregulation emerged as a dominant contributor to morbidity and family burden over time.  Longitudinal follow-up from birth through childhood highlights the dynamic and multisystem nature of distal chromosome 15 deletions.  This report expands on the phenotypic variability associated with 15q21.2-q22.2 deletions, as well as the importance of early genetic diagnosis, behavioral health support, anticipatory metabolic surveillance, and multidisciplinary management.  Continued study is needed to refine genotype-phenotype understanding and improve clinical management of rare chromosome disorders.

Recommended Citation

Conrad A. Longitudinal Behavioral and Metabolic Phenotype in a Child with a Distal Chromosome 15q21.3-22.2 Deletion. University of Lynchburg DMSc Doctoral Project Assignment Repository. 2026; 8(1).