Mowat-Wilson Syndrome

At a glance

It is an autosomal dominant complex developmental disorder characterized by the association of Hirschsprung’s disease, intellectual disability, and epilepsy. Other features include short stature, microcephaly, severe mental retardation, delayed motor development, epilepsy, and a wide spectrum of clinically heterogeneous features suggestive of neurocristopathies at the cephalic, cardiac, and vagal nerve levels. The presence of congenital heart disease, genitourinary anomalies and absence of the corpus callosum complete the diagnosis.

Synonyms

Hirschsprung Disease Syndrome; Hirschsprung Disease-Mental Retardation Syndrome.

History

This medical condition was first described by Dr D. R. Mowat and Dr M. J. Wilson in 1998.

Incidence

The exact incidence remains unknown. It seems to affect females and males in equal numbers.

Genetic inheritance

It is inherited as an autosomal dominant pattern. It is believed caused by a mutation in the SMAD interacting protein 1 (SMAD1P1) gene.

Clinical aspects

Patients present with short stature, microcephaly, hypertelorism and iris coloboma, ptosis, convergent strabismus, and wide nasal bridge. The cardiovascular system is always affected and involves a patent ductus arteriosus and ventricular septal defect. Neurologically, the presence of severe mental retardation and seizure activities must be noted. Most patients are affected with muscle hypotonia. Abdominal distension, megacolon, and vomiting are frequent features. Barium enema shows transition zone between aganglionic contracted segment and dilated proximal bowel.

Anesthetic considerations

Preoperatively, complete assessment of the cardiac function must be done. Use of antibiotic for cardiac protection is mandatory. Myoclonic seizures are frequent, and oral antiepileptic therapy must be evaluated carefully and possibly replaced by intravenous medications. The presence of hypotonia must be taken into consideration if muscle relaxation is indicated. No pharmacological contraindications are associated with this syndrome.

Other conditions to be considered

• Mietens-Weber Syndrome: Autosomal recessive disorder characterized by severe mental retardation, corneal opacity, nystagmus, strabismus, small pinched nose, flexion contracture of the elbows, dislocation of head of radius, abnormally short ulna and radius, and clinodactyly.

• Goldberg-Shprintzen Syndrome (GSS): It is also associated with Hirschsprung disease and intellectual disability. It is characterized by the presence of hypertelorism, cleft palate, iris coloboma, ptosis, arched eyebrows, and microcephaly. Other features include short stature and intellectual disabilities. It is inherited as an autosomal recessive condition.

References