Premium
Description of a family with X‐linked oculo‐auriculo‐vertebral spectrum associated with polyalanine tract expansion in ZIC3
Author(s) -
Trimouille Aurélien,
TingaudSequeira Angèle,
Lacombe Didier,
Duelund Hjortshøj Tina,
Kreiborg Sven,
Buciek Hove Hanne,
Rooryck Caroline
Publication year - 2020
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/cge.13811
Subject(s) - genetics , exome sequencing , goldenhar syndrome , phenotype , biology , genetic counseling , gene
Abstract Oculo‐auriculo‐vertebral spectrum (OAVS) [MIM:164210], or Goldenhar syndrome, is a developmental disorder associating defects of structures derived from the first and second branchial arches. The genetic origin of OAVS is supported by the description of rare deleterious variants in a few causative genes, and several chromosomal copy number variations. We describe here a large family with eight male members affected by a mild form of the spectrum, mostly auricular defects, harboring a hemizygous ZIC3 variant detected by familial exome sequencing: c.159_161dup p.(Ala55dup), resulting in an expansion of the normal 10 consecutive alanine residues to 11 alanines. Segregation analysis shows its presence in all the affected individuals, with a recessive X‐linked transmission. Whole‐genome sequencing performed in another affected male allowed to exclude linkage disequilibrium between this ZIC3 variant and another potential pathogenic variant in this family. Furthermore, by screening of a cohort of 274 OAVS patients, we found 1 male patient carrying an expansion of 10 to 12 alanines, a variant previously reported in patient presenting with VACTERL. Loss‐of‐function variants of ZIC3 are causing heterotaxy or cardiac malformations. These alanine expansion variants could have a different impact on the protein and thereby resulting in a different phenotype within the OAVS/VACTERL.