Prenatal diagnosis of megacystis microcolon intestinal hypoperistalsis syndrome by biochemical analysis of fetal urine

Exploring the complexities of megacystis-microcolon-intestinal hypoperistalsis syndrome: insights from genetic studies

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is an uncommon genetic disorder inherited in an autosomal recessive pattern that affects the muscles that line the bladder and intestines. The most common genes associated with MMIHS mutations are ACTG2, LMOD1, MYH11, MYL9, MYLK, and PDCL3. However, the complete genetic landscape of MMIHS still needs to be fully understood. The diagnosis of MMIHS can be challenging. However, advances in prenatal and diagnostic techniques, such as ultrasound and fetal urine analysis, have improved the ability to detect the syndrome early. Targeted next-generation sequencing (NGS) and other diagnostic tests can also diagnose MMIHS. The management of MMIHS involves addressing severe intestinal dysmotility, which often necessitates total parenteral nutrition (TPN), which can lead to complications such as hepatotoxicity and nutritional deficiencies. Multivisceral and intestinal transplantation has emerged as therapeutic options, offering the potential for improved outcomes and enteral autonomy. Understanding the genetic underpinnings of MMIHS is crucial for personalized care. While the prognosis varies, timely interventions and careful monitoring enhance patient outcomes. Genetic studies have given us valuable insights into the molecular mechanisms of MMIHS. These studies have identified mutations in genes involved in the development and function of smooth muscle cells. They have also shown that MMIHS is associated with defects in the signaling pathways that control muscle contraction. Continued research in the genetics of MMIHS holds promise for unraveling the complexities of MMIHS and improving the lives of affected individuals.

Prenatal diagnosis of megacystis-microcolon-intestinal hypoperistalsis syndrome

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare congenital disorder, acknowledged as the most debilitating form of chronic intestinal pseudoobstruction disorders. Because the disease is often fatal in the first years of life and the surviving individuals are dependent on supportive medical or surgical treatment, definite antenatal diagnosis is desirable. We report a case of prenatally diagnosed MMIHS and discuss the suspicious findings and diagnostic criteria that allow a rapid and definite prenatal diagnosis.

Compound heterozygous variants in MYH11 underlie autosomal recessive megacystis-microcolon-intestinal hypoperistalsis syndrome in a Chinese family

Megacystis-microcolon-intestinal-hypoperistalsis syndrome (MMIHS) is a rare and severe disorder characterized by functional obstruction in the urinary and gastrointestinal tract. The molecular basis of this condition has been defined recently. Heterozygous variants in ACTG2, homozygous mutations in LMOD1, MYLK, and MYH9 were related to the pathogenesis of the syndrome, which encodes proteins involved in the process of smooth muscle contraction, supporting a myopathic basis for the disease. Recent studies have identified homozygous or compound heterozygous variants in MYH11 as a candidate gene of MMIHS. In this report, we described a nonconsanguineous Chinese family with three male fetuses affected with megacystis. Trio-targeted exome sequencing identified compound heterozygous variants, c.2051 G > A (p.R684H) and c.3540_3541delinsTT (p.(E1180D, Q1181Ter)), in MYH11 (NM_001040114). The variants were inherited from the parents, respectively. Western blotting showed a marked decrease in MYH11 protein in the proband's umbilical cord tissue compared with the control sample. The study's results confirmed that MYH11 is a candidate gene for MMIHS with autosomal recessive (AR) inheritance and expanded the mutation spectrum for this clinical condition. Combining clinical phenotype with molecular diagnosis may enable the identification of candidate genes for potential monogenic diseases and facilitate accurate genetic counseling, informed decision-making, and prenatal diagnosis.