POGZ variants in neurodevelopmental delay: a case series on phenotype-genotype correlation.

Background:
POGO transposable element with ZNF domain (POGZ) gene is one of the most recurrently mutated genes in patients with neurodevelopmental delay (NDD). The number of reported POGZ variants continues to increase, and phenotypic reporting likely varies between different series.

Case description:
Five children with heterozygous POGZ variants, including two protein truncating variants (PTVs) and three missense variants, were found in our NDD patients with or without autism. A total of 201 patients carrying 158 different variants in the POGZ gene were reviewed to investigate the correlations between phenotypes and genotypes of these POGZ variants.

Conclusions:
POGZ gene PTVs were associated with a wider range of phenotypes and a higher frequency of some clinical features than missense variants. In addition, almost half of the PTVs located in the last two exons had more severe phenotypes than those in other exons. Missense variants were associated with fewer and milder phenotypes, but with a higher frequency of the autism phenotype. POGZ PTVs located in the last two exons, were linked to higher incidence rates of severe developmental delay (DD) and speech delay symptoms. Our study delineates the phenotypic spectrum associated with protein-truncating variants (PTVs) and missense variants in the POGZ gene, revealing a correlation with variable disease severity. These findings highlight the importance of genotype-driven strategies in clinical practice.