Hereditary neuropathy with liability to pressure palsies (HNPP) in a toddler presenting with toe-walking, pain and stiffness.

The typical clinical presentation of hereditary neuropathy with liability to pressure palsies is an adult-onset recurrent, painless monoparesis. Electrophysiological abnormalities--decreased nerve conduction velocities and delayed distal latencies--can be detected even in asymptomatic patients. We describe a toddler, who presented with asymmetric toe walking, painful cramps and stiffness in the legs. He had calf hypertrophy, brisk tendon reflexes and bilateral Babinski signs and the electrophysiological examination was normal. The unlikely diagnosis of hereditary neuropathy with liability to pressure palsies was reached 5 years later, when the boy started to complain of episodic numbness and weakness in the upper extremities. His father, paternal aunt and grandmother had similar symptoms, but they had never been investigated. The typical 1.5 Mb deletion on chromosome 17p11.2-12 was found in our patient and his affected relatives.