Megacystis-microcolon-intestinal hypoperistalsis syndrome and aganglionosis in trisomy 18.

[megacystis-microcolon-intestinal hypoperistalsis syndrome]

Ultrasonography at 23 weeks of gestation documented the presence of megacystis with horseshoe kidney , microcolon , intestinal malrotation , and decreased amniotic fluid volume . After pregnancy termination , an autopsy was performed . The external phenotype was diagnostic of the trisomy 18 syndrome confirmed by chromosome examination . The fetus also had a massively distended bladder with parchment-thin wall , microcolon , intestinal malrotation but no urethral obstruction or hydronephrosis . No ganglion cells were present in the colon or bladder . This has not been mentioned in other reported cases and , therefore , suggests pathogenic heterogeneity . The megacystis-microcolon -intestinal hypoperistalsis syndrome (MMIHS ) is a rare autosomal recessive condition of unknown pathogenesis whose genes map to 15 q 24 . Thus , its previously undescribed presence in trisomy 18 further suggests etiologic heterogeneity .