Gastrointestinal neuromuscular disorders

Gene: MYH11

Green List (high evidence)

Biallelic MYH11 variants have been associated with Megacystis-microcolon-intestinal hypoperistalsis syndrome 2 (OMIM:619351), and as limited Gen2Phen gene for the same condition. PMIDs 29575632 & 29575632 report five MYH11 variants in three unrelated cases of OMIM:619351. The unaffected parents of these cases were heterozygous for the MYH11 variant.

Created: 13 Aug 2024, 9:37 a.m. | Last Modified: 13 Aug 2024, 9:37 a.m.

Panel Version: 1.28

Comment on phenotypes: Monoallelic Aortic MYH11 variants are associated with: aneurysm, familial thoracic 4, OMIM:132900, MONDO:0007568 and Visceral myopathy 2, OMIM:619350, MONDO:0859157

Created: 13 Aug 2024, 9:25 a.m. | Last Modified: 13 Aug 2024, 9:25 a.m.

Panel Version: 1.26

Green List (high evidence)

Heterozygous dominant negative MYH11 pathogenic variants have been associated with thoracic aortic aneurysm and dissection while biallelic null alleles have been associated with megacystis microcolon intestinal hypoperistalsis syndrome. Recent report of two families with heterozygous protein‐elongating MYH11 variants affecting the SM2 isoforms of MYH11 as a cause for severe gastrointestinal dysmotility. The authors hypothesise that the mechanistic pathogenesis of this disease, dominant hypercontractile loss‐of‐function, is distinct from those implicated in other diseases involving MYH11 dysfunction.
Sources: Expert list

Created: 23 Apr 2020, 3:30 a.m.

Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal

Phenotypes
Megacystis microcolon intestinal hypoperistalsis syndrome, autosomal recessive; Dominant smooth muscle dysmotility syndrome

Publications

• 31944481
• 29575632

Variants in this GENE are reported as part of current diagnostic practice