TY - JOUR

T1 - Rare novel variants in the ZIC3 gene cause X-linked heterotaxy

AU - Paulussen, Aimee D C

AU - Steyls, Anja

AU - Vanoevelen, Jo

AU - van Tienen, Florence Hj

AU - Krapels, Ingrid P C

AU - Claes, Godelieve Rf

AU - Chocron, Sonja

AU - Velter, Crool

AU - Tan-Sindhunata, Gita M

AU - Lundin, Catarina

AU - Valenzuela, Irene

AU - Nagy, Balint

AU - Bache, Iben

AU - Maroun, Lisa Leth

AU - Avela, Kristiina

AU - Brunner, Han G

AU - Smeets, Hubert J M

AU - Bakkers, Jeroen

AU - van den Wijngaard, Arthur

PY - 2016/12

Y1 - 2016/12

N2 - Variants in the ZIC3 gene are rare, but have demonstrated their profound clinical significance in X-linked heterotaxy, affecting in particular male patients with abnormal arrangement of thoracic and visceral organs. Several reports have shown relevance of ZIC3 gene variants in both familial and sporadic cases and with a predominance of mutations detected in zinc-finger domains. No studies so far have assessed the functional consequences of ZIC3 variants in an in vivo model organism. A study population of 348 patients collected over more than 10 years with a large variety of congenital heart disease including heterotaxy was screened for variants in the ZIC3 gene. Functional effects of three variants were assessed both in vitro and in vivo in the zebrafish. We identified six novel pathogenic variants (1,7%), all in either male patients with heterotaxy (n=5) or a female patient with multiple male deaths due to heterotaxy in the family (n=1). All variants were located within the zinc-finger domains or leading to a truncation before these domains. Truncating variants showed abnormal trafficking of mutated ZIC3 proteins, whereas the missense variant showed normal trafficking. Overexpression of wild-type and mutated ZIC protein in zebrafish showed full non-functionality of the two frame-shift variants and partial activity of the missense variant compared with wild-type, further underscoring the pathogenic character of these variants. Concluding, we greatly expanded the number of causative variants in ZIC3 and delineated the functional effects of three variants using in vitro and in vivo model systems.

AB - Variants in the ZIC3 gene are rare, but have demonstrated their profound clinical significance in X-linked heterotaxy, affecting in particular male patients with abnormal arrangement of thoracic and visceral organs. Several reports have shown relevance of ZIC3 gene variants in both familial and sporadic cases and with a predominance of mutations detected in zinc-finger domains. No studies so far have assessed the functional consequences of ZIC3 variants in an in vivo model organism. A study population of 348 patients collected over more than 10 years with a large variety of congenital heart disease including heterotaxy was screened for variants in the ZIC3 gene. Functional effects of three variants were assessed both in vitro and in vivo in the zebrafish. We identified six novel pathogenic variants (1,7%), all in either male patients with heterotaxy (n=5) or a female patient with multiple male deaths due to heterotaxy in the family (n=1). All variants were located within the zinc-finger domains or leading to a truncation before these domains. Truncating variants showed abnormal trafficking of mutated ZIC3 proteins, whereas the missense variant showed normal trafficking. Overexpression of wild-type and mutated ZIC protein in zebrafish showed full non-functionality of the two frame-shift variants and partial activity of the missense variant compared with wild-type, further underscoring the pathogenic character of these variants. Concluding, we greatly expanded the number of causative variants in ZIC3 and delineated the functional effects of three variants using in vitro and in vivo model systems.

U2 - 10.1038/ejhg.2016.91

DO - 10.1038/ejhg.2016.91

M3 - Journal article

C2 - 27406248

VL - 24

SP - 1783

EP - 1791

JO - European Journal of Human Genetics

JF - European Journal of Human Genetics

SN - 1018-4813

IS - 12

ER -