2q13 Distal Microdeletion: Considering Evidence for an Emerging Syndrome Versus Susceptibility Locus: Twenty‐Five New Cases and Review of the Literature

ABSTRACT This study investigates distal 2q13 microdeletion, presenting the largest cohort to date, including prenatal cases, alongside a comprehensive literature review. A retrospective analysis was conducted on distal 2q13 microdeletions from clinical charts and laboratory reports. The cohort was divided into “clinically indicated” and “not‐clinically indicated” groups based on the reason for chromosomal microarray testing. Clinical cases from medical literature were reviewed and compared with our cohort. The study included 25 cases: 17 index patients and 8 family members, with 47% males and 53% females. Of these, 2 were postnatal and 15 were prenatal. In the “clinically indicated” group, 35% had abnormalities on prenatal ultrasound, while 65% in the “not‐clinically indicated” group had no major anomalies. Inheritance was 50% paternal in the “clinically indicated” group, and in the “not‐clinically indicated” group, 44% paternal, 22% maternal, and 33% de novo . Symptoms varied from asymptomatic to severe developmental issues. Literature review identified 51 postnatal cases, with intellectual disability, and dysmorphism being common features. Familial cases showed 20% de novo , 20% maternal, 21.5% paternal, and 40% unknown inheritance. Distal 2q13 microdeletion is linked to cognitive impairment risk and should be reported in test results based on parental preferences, requiring special considerations for clinical classification and reporting.