"Liu-Liang-Chung" syndrome with multiple congenital anomalies and the distinctive craniofacial features caused by dominant ZEB2 gene gain mutation

Abstract

Background: Contiguous gene gain syndrome including entire ZEB2 may be a novel syndrome. In the past, there were no easily distinct and recognizable features as a guide for precise clinical and genetic diagnosis of the syndrome.

Case presentation: We report a novel case with the syndrome with a novel de novo 22.16 Mb duplication at 2q21.2-q24.1. The syndrome is characterized by multiple anomalies including the same typical craniofacial phenotype that is entirely different from Mowat-Wilson syndrome (MWS), and other quite similar features of MWS consisting of development delay, congenital heart disease, abdominal abnormalities, urogenital abnormalities, behavioral problems and so on, in which the distinctive craniofacial features can be more easily recognized.

Conclusions: Contiguous gene gain syndrome including entire ZEB2 characterized with similar multiple congenital anomalies of MWS and the distinctive craniofacial features is mainly caused by large 2q22 repeats including ZEB2 leading to dominant singe ZEB2 gene gain mutation, which is recommended to be named "Liu-Liang-Chung" syndrome. We diagnose this novel syndrome to distinguish it from MWS. Some variable additional features in the syndrome including remarkable growth and development retardation and protruding ears were recognized for the first time.

Keywords: 2q22; Distinctive craniofacial features; Increase of gene dosage; Liu-Liang-Chung syndrome; ZEB2.