Early lethal Dejerine-Sottas syndrome in a 13-year-old girl with a point mutation in the MPZ-gene also found in the asymptomatic father

Introduction: Hereditary neuropathies are the most frequent monogenetically inherited nervous diseases. It has been shown that certain mutations can lead to different phenotypes. Mutations in the Myelin-Protein-Zero (MPZ) gene and, to a lesser extent, in the Myelin-Protein-22 (PMP22) gene have been described in Dejerine-Sottas-syndrome (DSS).

Case Report: We report on a 13-year-old girl with congenital hypotonia and initial feeding difficulties. She never was able to get to her feet alone but learned to walk at the age of 18 months. DSS was diagnosed by a reduction in the peroneal nerve conduction velocity (15 m/s) and by histopathology. Later a point mutation in the MPZ gene was found. Mutations in other genes described in the literature could be excluded in the girl. After years with recurrent pneumoniae weakening progressed rapidly at the age of 13. Within a few months she was laid up with progressive scoliosis and dyspnoea. The girl died after the attempt of stabilizing her scoliosis operatively. The mother had a normal trinucleotide sequence in the MPZ gene, but her father had the same mutation as his clinically affected daughter. The father has no signs of neuropathy.

Conclusion: The mutation found in this girl would have been considered the cause of her neuropathy unless her parents were studied as well. As this particular mutation is not yet described it is not clear weather this mutation merely is a polymorphism or weather it is a polygenetic risk factor which caused the neuropathy together with another not as yet discovered mutation.

Keywords: Dejerine-Sottas syndrome, PMP-22-mutation, polymorphism