Roussy-Lévy Syndrome: a case of genotype-fenotype correlation

Roussy-Lévy Syndrome (RLS) is an uncommon variant of the Charcot-Marie-Tooth (CMT) type 1 (CMT-1B) disease, a dominantly inherited form of neuropathy. This condition was originally described in 1926 by Gabrielle Roussy and Gustave Lévy. Herein, we describe a novel case of RLS, outside the original kindred depicted by Roussy and Lévy. In our patient, the early onset of sensory gait ataxia with little progression to motor symptoms somehow differed from the classical and more severe picture of CMTs. In addition, mild ENG/EMG neuropathic signs, postural and kinetic tremor in upper limbs, suggested a clinical diagnosis of RLS. The identification of the Asn131Lys MPZ gene mutation, the same identified in the original Roussy-Lévy family, completed the diagnostic picture. Our case reinforces this genotype-phenotype correlation: the Asn131Lys mutation is indeed only related to a mild CMT phenotype of the RSL type. Thus, in a world of ever changing predictiveness of genetic results, the very clinical original description made in a “pre-DNA” era (1926) appears to anticipate a specific DNA mutation.