@article {393,
	title = {Loss-of-Function Variants in MYLK Cause Recessive Megacystis Microcolon Intestinal Hypoperistalsis Syndrome.},
	journal = {Am J Hum Genet},
	volume = {101},
	year = {2017},
	month = {2017 Jul 06},
	pages = {123-129},
	abstract = {<p>Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a congenital disorder characterized by loss of smooth muscle contraction in the bladder and intestine. To date, three genes are known to be involved in MMIHS pathogenesis: ACTG2, MYH11, and LMOD1. However, for approximately 10\% of affected individuals, the genetic cause of the disease is unknown, suggesting that~other~loci are most likely involved. Here, we report on three MMIHS-affected subjects from two consanguineous families with~no~variants~in the known MMIHS-associated genes. By performing homozygosity mapping and whole-exome sequencing, we found~homozygous variants in myosin light chain kinase (MYLK) in both families. We identified a 7~bp duplication (c.3838_3844dupGAAAGCG~[p.Glu1282_Glyfs51]) in one family and a putative splice-site variant (c.3985+5C>A) in the other. Expression studies and splicing assays indicated that both variants affect normal MYLK expression. Because MYLK encodes an important kinase required for myosin activation and subsequent interaction with actin filaments, it is likely that in its absence, contraction of smooth muscle cells is impaired. The existence of a conditional-Mylk-knockout mouse model with severe gut dysmotility and abnormal function of the bladder supports the involvement of this gene in MMIHS pathogenesis. In aggregate, our findings implicate MYLK as a gene involved in the recessive form of MMIHS, confirming that this disease of the visceral organs is heterogeneous with a myopathic origin.</p>},
	keywords = {Abnormalities, Multiple, Base Sequence, Colon, Female, Genes, Recessive, Homozygote, Humans, Intestinal Pseudo-Obstruction, Male, Mutation, Myosin-Light-Chain Kinase, Pedigree, Urinary Bladder},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2017.05.011},
	author = {Halim, Danny and Brosens, Erwin and Muller, Fran{\c c}oise and Wangler, Michael F and Beaudet, Arthur L and Lupski, James R and Akdemir, Zeynep H Coban and Doukas, Michael and Stoop, Hans J and de Graaf, Bianca M and Brouwer, Rutger W W and van Ijcken, Wilfred F J and Oury, Jean-Fran{\c c}ois and Rosenblatt, Jonathan and Burns, Alan J and Tibboel, Dick and Hofstra, Robert M W and Alves, Maria M}
}
