@article {122,
	title = {Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2.},
	journal = {Am J Hum Genet},
	volume = {97},
	year = {2015},
	month = {2015 Nov 05},
	pages = {647-60},
	abstract = {<p>Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In~vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In~vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants. </p>},
	keywords = {Alleles, Animals, Female, Fluorescent Antibody Technique, Genetic Linkage, Hearing Loss, Unilateral, Humans, Male, Mice, Mutation, NIH 3T3 Cells, Pedigree, Phenotype, Prognosis, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Stem Cell Factor, Waardenburg Syndrome},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2015.09.011},
	author = {Zazo Seco, Celia and Serr{\~a}o de Castro, Luciana and van Nierop, Josephine W and Mor{\'\i}n, Mat{\'\i}as and Jhangiani, Shalini and Verver, Eva J J and Schraders, Margit and Maiwald, Nadine and Wesdorp, Mieke and Venselaar, Hanka and Spruijt, Liesbeth and Oostrik, Jaap and Schoots, Jeroen and van Reeuwijk, Jeroen and Lelieveld, Stefan H and Huygen, Patrick L M and Insenser, Mar{\'\i}a and Admiraal, Ronald J C and Pennings, Ronald J E and Hoefsloot, Lies H and Arias-V{\'a}squez, Alejandro and de Ligt, Joep and Yntema, Helger G and Jansen, Joop H and Muzny, Donna M and Huls, Gerwin and van Rossum, Michelle M and Lupski, James R and Moreno-Pelayo, Miguel Angel and Kunst, Henricus P M and Kremer, Hannie}
}
