2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-Fifth Case of <em>MYH11</em>-Associated Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome Identified in Patient with Missense Variant and Whole Gene Deletion

Fifth Case of MYH11-Associated Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome Identified in Patient with Missense Variant and Whole Gene Deletion

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Pdf Summary

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare disorder characterized by urinary and gastrointestinal obstruction. The condition often results in a poor prognosis, with most individuals passing away in their first year of life. While the genetic cause is unknown in the majority of cases, several genes related to muscle function have been associated with MMIHS. This report presents the fifth case of MMIHS associated with the MYH11 gene.<br /><br />The patient in this case was diagnosed prenatally with megacystis, bilateral hydronephrosis, and intrauterine growth restriction. Genetic testing revealed a deletion of the MYH11 gene and a likely pathogenic missense variant in MYH11. The variant was inherited from the mother, while the deletion was de novo. The patient underwent multiple surgeries and experienced global developmental delay.<br /><br />This case adds to the limited knowledge about MMIHS caused by variants in the MYH11 gene. Previously reported cases have demonstrated various additional features, such as lung hypoplasia, mydriasis, hearing loss, lung disease, pulmonary hypertension, and aortic dilation. Each case has contributed to the understanding of the diverse clinical presentation associated with this condition.<br /><br />Overall, this report highlights the importance of genetic testing in diagnosing MMIHS and identifying specific gene variants. Understanding the genetic underpinnings of the disorder can aid in providing appropriate medical management and counseling for families affected by MMIHS. Further research is needed to fully grasp the clinical spectrum and long-term outcomes of individuals with MMIHS.

Asset Subtitle

Presenting Author - Kathleen Shields, MS; Co-Author - Hope Northrup, MD, FFACMG;

Meta Tag

Clinical History

Congenital Anomaly

Genetic Testing

Genitourinary malformations

Malformation

Microarray

NextGen Sequencing

Phenotype

Sequencing

Co-Author Hope Northrup, MD, FFACMG

Presenting Author Kathleen Shields, MS

Keywords

MMIHS

urinary obstruction

gastrointestinal obstruction

genetic cause

MYH11 gene

prenatal diagnosis

genetic testing

developmental delay

lung hypoplasia

clinical presentation