P4HTM

Clinical Characteristics

Most common features are in bold text

General:
•    Global developmental delay (100% of cases)
•    Obesity (53% of cases)

Neurological:
•    Intellectual disability
•    Hypotonia (100% of cases)
•    Dysautonomia
•    Epilepsy (50% of cases)
•    MRI abnormalities (53.8% of cases)
             o    Brain dysmyelination
             o    Brain atrophy

Respiratory:
•    Hypoventilation (65% of cases)
•    Sleep apnea
•    Recurrent pneumonia

Abdomen:
•    Gastrointestinal reflux disease
•    Constipation

Skeletal:
•    Scoliosis

Head and Neck:
•    Variable mild facial dysmorphism
•    Abnormalities of the eye, including nystagmus, poor vision, and abnormal eye movements