Clinical and electrophysiological features in a French family presenting with seipinopathy

Seipinopathies are a group of inherited diseases affecting upper and lower motor neurons due to mutations in the Berardinelli-Seip congenital lipodystrophy 2 gene (BSCL2). We report a French family carrying the N88S mutation in the BSCL2 gene. A 12-yr-old girl complained of bilateral asymmetrical pes cavus with right hand motor deficit and amyotrophy, asymmetrical leg amyotrophy and pyramidal signs. Electrophysiological examination showed axonal asymmetrical motor neuropathy with distal predominance. Her father complained of right hand rest tremor with bilateral hand weakness. Physical examination revealed left leg, hand and forearm amyotrophy, akinesia and right arm rigidity, brisk reflexes in the lower limbs and bilateral Babinski sign. Nerve conduction studies showed distal asymmetrical axonal neuropathy with slight sensitive impairment with moderate decrease of nerve conduction velocity in some nerves. DNA sequencing revealed the presence of the known N88S mutation in the BSCL2 gene (dideoxy-nucleotide method on a 3730 DNA Analyzer, Life Technologies). BSCL2 gene mutations are associated with a wide spectrum of clinical and electrophysiological phenotypes and should be suspected in cases of distal hereditary motor neuropathy with pyramidal signs or early hand involvement. There may also be associated mild demyelination which may vary in severity within the same family. Clinical diagnosis was more difficult in this particular case due to the association with Parkinson symptoms.