Type 3/Dejerine Sottas mutations update

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Research Abstract from Acta Neurol Scand. 2004 Sep;110(3):196-9.

Dejerine-Sottas' neuropathy caused by the missense mutation PMP22

Ser72Leu.

Marques W Jr, Neto JM, Barreira AA.

Department of Neurology, School of Medicine of Ribeirao Preto,

University of Sao o, Sao o, Brazil.

Objective - To describe a patient with the Dejerine-Sottas' syndrome due

to a de novo Ser72Leu amino acid substitution in the PMP22 protein and

summarize the phenotype associated with this frequent mutation.

Case report - The proband has a medical history of early onset, severe,

and progressive demyelinating neuropathy, accompanied by mild ptosis and

limitations of eye movements. Ulnar nerve motor conduction velocities

were extremely reduced (2.6 and 2.2 m/s), and the sural nerve biopsy

showed onion bulbs and thinly myelinated axons. Duplication of

chromosome 17p11.2 was ruled out, and the Ser72Leu substitution was

found upon sequencing the PMP22 gene.

Conclusion - The Ser72Leu substitution is being confirmed as the most

frequent point mutation in the PMP22 gene. This 'hot spot' should be

considered in the strategy of looking for point mutations in the

hereditary demyelinating neuropathies.