A TUBB6 mutation is associated with autosomal dominant non-progressive congenital facial palsy, bilateral ptosis and velopharyngeal dysfunction

TY - JOUR

T1 - A TUBB6 mutation is associated with autosomal dominant non-progressive congenital facial palsy, bilateral ptosis and velopharyngeal dysfunction

AU - Fazeli, Walid

AU - Herkenrath, Peter

AU - Stiller, Barbara

AU - Neugebauer, Antje

AU - Fricke, Julia

AU - Lang-Roth, Ruth

AU - Nürnberg, Gudrun

AU - Thoenes, Michaela

AU - Becker, Jutta

AU - Altmüller, Janine

AU - Volk, Alexander E

AU - Kubisch, Christian

AU - Heller, Raoul

N1 - © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

PY - 2017/10/15

Y1 - 2017/10/15

N2 - Congenital cranial dysinnervation disorders (CCDDs) comprise a heterogeneous spectrum of diseases characterized by congenital, non-progressive impairment of eye, eyelid and/or facial movements including Möbius syndrome, Duane retraction syndrome, congenital ptosis, and congenital fibrosis of the extraocular muscles. Over the last 20 years, several CCDDs have been identified as neurodevelopmental disorders that are caused by mutations of genes involved in brain and cranial nerve development, e.g. KIF21A and TUBB3 that each plays a pivotal role for microtubule function. In a five-generation pedigree, we identified a heterozygous mutation of TUBB6, a gene encoding a class V tubulin which has not been linked to a human hereditary disease so far. The missense mutation (p.Phe394Ser) affects an amino acid residue highly conserved in evolution, and co-segregates with a phenotype characterized by congenital non-progressive bilateral facial palsy and congenital velopharyngeal dysfunction presenting with varying degrees of hypomimia, rhinophonia, impaired gag reflex and bilateral ptosis. Expression of the mutated protein in yeast led to an impaired viability compared to wildtype cells when exposed to the microtubule-poison benomyl. Our findings enlarge the spectrum of tubulinopathies and emphasize that mutations of TUBB6 should be considered in patients with congenital non-progressive facial palsy. Further studies are needed to verify whether this phenotype is indeed part of the CCDD spectrum.

AB - Congenital cranial dysinnervation disorders (CCDDs) comprise a heterogeneous spectrum of diseases characterized by congenital, non-progressive impairment of eye, eyelid and/or facial movements including Möbius syndrome, Duane retraction syndrome, congenital ptosis, and congenital fibrosis of the extraocular muscles. Over the last 20 years, several CCDDs have been identified as neurodevelopmental disorders that are caused by mutations of genes involved in brain and cranial nerve development, e.g. KIF21A and TUBB3 that each plays a pivotal role for microtubule function. In a five-generation pedigree, we identified a heterozygous mutation of TUBB6, a gene encoding a class V tubulin which has not been linked to a human hereditary disease so far. The missense mutation (p.Phe394Ser) affects an amino acid residue highly conserved in evolution, and co-segregates with a phenotype characterized by congenital non-progressive bilateral facial palsy and congenital velopharyngeal dysfunction presenting with varying degrees of hypomimia, rhinophonia, impaired gag reflex and bilateral ptosis. Expression of the mutated protein in yeast led to an impaired viability compared to wildtype cells when exposed to the microtubule-poison benomyl. Our findings enlarge the spectrum of tubulinopathies and emphasize that mutations of TUBB6 should be considered in patients with congenital non-progressive facial palsy. Further studies are needed to verify whether this phenotype is indeed part of the CCDD spectrum.

KW - Journal Article

U2 - 10.1093/hmg/ddx296

DO - 10.1093/hmg/ddx296

M3 - SCORING: Journal article

C2 - 29016863

VL - 26

SP - 4055

EP - 4066

JO - HUM MOL GENET

JF - HUM MOL GENET

SN - 0964-6906

IS - 20

ER -