Prenatally Diagnosed De Novo Interstitial Duplication in 2p21p24.3 with Unique Manifestations: Case Report

This case broadens the clinical spectrum of partial trisomy 2p by documenting unique features, including subglottic haemangioma, behavioural symptoms, and preauricular pit. It highlights the value of integrating prenatal diagnostics with detailed postnatal phenotypic assessment to improve understanding of genotype-phenotype correlations in rare chromosomal duplications. Although the <i>PPP1CB</i> gene within the region is considered a plausible candidate for explaining some of the patient's cardinal features, dysmorphism (prominent forehead, preauricular ear pits, low-set, posteriorly rotated ears), cardiac-neurological problems, other genes associated with defined syndromes - whose clinical manifestations overlap to varying degrees - were also considered as potential contributors to the clinical picture, such as <i>MYCN</i>, <i>DNMT3A</i>, <i>DPYSL5</i>, and <i>SOS1</i>. These insights can aid clinicians in genetic counselling, anticipatory guidance, and management of similar cases in the future.