Management of children with Phelan-McDermid syndrome
Phelan-McDermid syndrome is caused by the deletion or disruption of chromosome region 22q13.3. Although most individuals with this syndrome have no life-threatening anomalies, many physical and developmental defects require intervention. Neurologic problems include neonatal hypotonia, arachnoid cysts, delayed myelination, frontal lobe hypoplasia, agenesis of the corpus callosum and ventriculomegaly which may require neurologic consultation. Arachnoid cysts, found in over 15% of children, may present as increased intracranial pressure with incessant crying bouts, irritability, severe headaches, cyclic vomiting or seizures. Imaging studies are indicated to detect brain abnormalities. Hearing loss is often suspected due to multiple ear infections, delayed speech, and regression in speech. However, over 80% of children have normal hearing. Delayed processing time and difficulty distinguishing spoken words from background noise are often misinterpreted as hearing loss. Aggressive therapy to improve cognitive skills and communication are warranted. Long-term therapies to improve muscle tone, coordination and upper body strength are beneficial. Hypotonia may contribute to swallowing problems and to aspiration, warranting evaluation by a gastroenterologist. Gastrointestinal reflux is present in 30% of patients but is difficult to diagnose because many affected children do not indicate the discomfort normally associated with reflux. Other GI problems include chronic diarrhea and constipation that are unrelated to diet. Recurrent urinary tract infections, cystic kidneys, dysplastic kidneys, hydronephrosis, and renal vesicoureteral reflux are also found. A baseline renal ultrasound and VSUG are recommended to monitor for renal abnormalities. The incidence of lymphedema and recurrent cellulitis are increased and require medical and possibly surgical management. Overall, the increased tolerance to pain and lack of expressive language makes the management of children with deletion 22q13 particularly difficult. Parents, therapists, and medical professionals must be vigilant in their monitoring and care of children with Phelan-McDermid syndrome.