Mosaic trisomy 22 associated with total colonic aganglionosis and malrotation

Abnormalities of chromosome 22 karyotype have been reported to be associated with both malrotation and aganglionosis. However, although malrotation has been reported to occur in the rare mosaic trisomy 22, Hirschsprung's disease has not. We present a case of mosaic trisomy 22 that presented during the neonatal period with malrotation and total colonic aganglionosis, and we discuss the possible pathogenesis of both conditions in the light of this rare genetic abnormality. The association of total colonic aganglionosis and mosaic trisomy 22 has not previously been reported.

A male neonate with an antenatal diagnosis of de novo mosaic trisomy 22 underwent a laparotomy with correction of malrotation and midgut volvulus on day 3 of life. Rectal biopsy was performed because he had not passed meconium. This revealed Hirschsprung's disease; an ileostomy was formed, and histology confirmed aganglionosis as far as the terminal ileum. At 6 months, a modified Lester Martin Duhamel pull-through was performed. He is showing normal development at follow-up.

We recommend an increased index of suspicion of Hirschsprung's disease and malrotation in patients with mosaic trisomy 22 until further evidence can establish or exclude a meaningful relationship.