Symptoms of HMSN
Hereditary Motor and Sensory Neuropathy Type 2, HMSN2, CMT2A2 (axonal) - MFN2
Klinische Symptomatik
The clinical features of Axonal Hereditary Motor and Sensory Neuropathy Type 2 (HMSN2, CMT2A2) belong to those of classic HMSN. Age of onset and progression of the disease can vary greatly, even within one family, and a clinical or electrophysiological history of the disease in the family need not be present. This primarily axonal neuropathy progresses slowly and normally begins in childhood or adolescence with distal paresis and atrophy in the lower extremities.
In contrast to HMSN1, sensibility often remains unaffected and motor nerve conduction velocities show only minor delay (> 40m/s), if any. Optic atrophy and/or loss of vision can also occur and, in some cases, subside; due to the presence of these additional symptoms, the disease is also classified as HMSN Type 6.
Genetik
CMT2A follows an autosomal dominant pattern of inheritance and is caused by mutations in the MFN2 gene (Mitofusin 2) located on chromosome 1p36.2. The gene consists of 17 coding exons.
Häufigkeit
MFN2 mutations are found in 10-20% of patients with axonal CMT neuropathy, thus representing the most common cause of the axonal form of HMSN.
Diagnostik
Indikation
Methodik
Analysis of all coding regions and bordering intronic regions as well as the 5´ and 3´ untranslated regions of the MFN2 gene using DNA sequencing.
Analysis of the gene dose and individual exons using MLPA.
Material
2 - 4 ml of EDTA blood
Dauer
4 - 6 weeks
Versand
Mail at room temperature or lab-based courier.
Beratung
For genetic counselling, please call +49 (0)89/309 08 86-0