A De Novo Missense Variant in POU3F2 Identified in a Child with Global Developmental Delay.

Many genetic and nongenetic causes for developmental delay in childhood could be identified. Often, however, the molecular basis cannot be elucidated. As next-generation sequencing is becoming more frequently available in a diagnostic context, an increasing number of genetic variations are found as causative in children with developmental delay.We performed trio exome sequencing in a girl with developmental delay and minor dysmorphological features. Using a filter for de novo variants, the heterozygous missense variant c.812A>T, p.(Glu217Val) was found in the candidate gene POU3F2 in our patient. POU3F2 plays an important role in neuronal differentiation and hormonal regulation. To date, it has not been associated with monogenic disorders. Studies on Pou3f2 knockout mice highlighted the importance of this protein in the development of the brain. Furthermore, microdeletions with an overlapping region including only POU3F2 and FBXL4 were linked to developmental delay in six unrelated families. Therefore, POU3F2 is a strong candidate gene for developmental delay, although functional assays proving this assumption still have to be done.

It Is Not Carved in Stone-The Need for a Genetic Reevaluation of Variants in Pediatric Cardiomyopathies.

(1) Background: In cardiomyopathies, identification of genetic variants is important for the correct diagnosis and impacts family cascade screening. A classification system was published by the American College of Medical Genetics and Genomics (ACMG) in 2015 to standardize variants' classification. The aim of the study was to determine the rate of reclassification of previously identified variants in patients with childhood-onset cardiomyopathies. (2) Methods: Medical records of patients and their relatives were screened for clinical and genetic information at the Department of Congenital Heart Defects and Pediatric Cardiology, German Heart Center Munich. Patients without an identified genetic variant were excluded from further analyses. Previously reported variants were reevaluated by the ACMG criteria in November 2021. (3) Results: Data from 167 patients or relatives of patients with childhood-onset cardiomyopathy from 137 families were analyzed. In total, 45 different genetic variants were identified in 71 individuals. Classification changed in 29% (13/45) with the greatest shift in "variants of unknown significance" to "(likely) benign" (9/13). (4) Conclusions: In patients with childhood-onset cardiomyopathies, nearly a third of reported genetic variants change mostly to more benign classes upon reclassification. Given the impact on patient management and cascade screening, this finding underlines the importance of continuous genetic counseling and variant.