Coexisting genetic findings in a cohort of patients with laboratory confirmation of 22q11.2 deletion syndrome

22q11.2DS is the most common microdeletion disorder, affecting ~ 1:3000-6000 live births, characterized by high phenotypic variability with multiorgan involvement With the advent of WGS, the diagnosis of multiple genetic disorders in a single individual is becoming more widely recognized (~ 4-6%) In patients who already have a genetic diagnosis, a secondary genetic disorder can be found as an explanation for clinical features atypical for the known genetic anomaly Patients with atypical features should prompt consideration of coexisting diagnoses due to additional genome-wide mutations, CNVs, or mutations on the other allele unmasking autosomal recessive conditions The presence of a dual diagnosis may exacerbate symptoms and impacts clinical management Our study showed a remarkable prevalence of coexisting genetic anomalies in patients with 22q11.2 DS or 22q11.2DuplS Indication for genome-wide microarray in lieu of MLPA or FISH, especially in patients with atypical findings for the 22q11.2 deletion/duplication syndrome or with familial recurrence of other genetic conditions Interestingly, in our cohort, 2 patients present a second anomaly affected the function of a gene that regulates cells proliferation (NF1 and RET), resulting in a predisposition of developing tumors and maybe genetic fragility Accurate diagnosis of a additional genetic conditions allows for more appropriate and personalized medical management and for suitable genetic counseling of families.