Mowat-Wilson Syndrome and Asplenia

Recommendation for MWS Patients to Get Evaluated for Absent Spleen

Recently, several reports have highlighted a rare finding in individuals with Mowat-Wilson syndrome (MWS), namely absent or missing spleen. The spleen is an organ that filters the blood and can help fight certain types of bacterial infections. The spleen is located in the left upper abdomen but frequently not felt on physical examination. Individuals who do not have a spleen can live long and healthy lives, but may be at increased risk for certain infections. Additionally, individuals without a spleen should be vaccinated against certain bacteria that can cause serious infections.

Now that we are aware of this finding, we recommend that all individuals with MWS be evaluated for an absent spleen. The test is easy to do and noninvasive. The best way to look for the spleen is through an ultrasound, an imaging technique that does not have any known side effects. Many individuals with MWS may have had this study done in the past. For example, if a person had an ultrasound scan to look at the kidneys, the spleen may have been imaged as well. If a person has had an “abdominal ultrasound” in the past, this should have evaluated for the presence of a spleen. If only a “renal ultrasound” was done, this may not have looked for the presence of a spleen. Please talk with your healthcare provider about whether an ultrasound that looks for the spleen has already been done. Absence of the spleen in MWS is typically something someone would have from birth. If a spleen was seen on ultrasound at some point (even years ago), then a person does not need to have the ultrasound repeated, unless that person’s healthcare provider is concerned the person has symptoms of a non-working spleen. The spleen can stop working for reasons unrelated to MWS, but people with MWS are not known to be at increased risk to have this particular complication.