A homozygous nonsense HECW2 variant is associated with neurodevelopmental delay and intellectual disability

E3 ubiquitin ligase HECW2: a promising target for tumour therapy

Ubiquitination is a prevalent post-translational modification that plays a crucial role in a wide range of pathophysiological processes, including cell proliferation, apoptosis, autophagy, immune response, and DNA damage repair. Among the enzymes involved in ubiquitination, E3 ubiquitin ligases are particularly significant, serving as key regulators of numerous diseases, including tumours. This review focuses on HECW2 (HECT, C2, and WW domain-containing E3 ubiquitin protein ligase 2, also known as NEDL2), providing a comprehensive overview of its interactors and its pathological roles in tumorous cancer and other diseases. The insights gained from this review may contribute to the development of novel treatment strategies for various diseases, particularly tumours.

First splicing variant in HECW2 with an autosomal recessive pattern of inheritance and associated with NDHSAL

We report the clinical and genetic features of a Caucasian girl who presented a severe neurodevelopmental disorder with drug-resistant epilepsy, hypotonia, severe gastro-esophageal reflux and brain MRI anomalies. WES uncovered a novel variant in homozygosis (g.197092814_197092824delinsC) in HECW2 gene that encodes the E3 ubiquitin-protein ligase HECW2. This protein induces ubiquitination and is implicated in the regulation of several important pathways involved in neurodevelopment and neurogenesis. Furthermore, de novo heterozygous missense variants in this gene have been associated with NDHSAL. The homozygous variant of our patient disrupts the splice donor site of intron 22 and causes the elimination of exon 22 (r.3766_3917+1del) leading to an in-frame deletion of the protein (p.Leu1256_Trp1306del). Functional studies showed a two-fold increase of its RNA expression, while the protein expression level was reduced by 60%, suggesting a partial LOF mechanism of pathogenesis. Thus, this is the first patient with NDHSAL caused by an autosomal recessive splicing variant in HECW2. This article is protected by copyright. All rights reserved.