Abovementioned HNA symptoms, positive family history
Hereditary Neuralgic Amyotrophie, HNA - SEPT9
Clinical Features
Hereditary neuralgic amyotrophy (HNA) affects the shoulders and upper arms and is thus easily distinguishable from HMSN1:
• Recurrent burning pain in shoulder and arm
• Painful inflammation of N. plexus in the arm region
• Elektrophysiologically, an axonal lesion of Plexus brachialis is dectable
• The disappearance of pain is followed by pareses.
• Recovery from pareses within 3-4 months.
• Hypotelorismus and cleft palate in rare cases
HNA is occasionally accompanied by a hereditary neuropathy with liability to pressure palsies (HNPP) caused by deletion of the PMP22 gene (chromosome 17p12). HNPP may show signs of a plexus lesion.
Genetic Information
HNA follows a pattern of autosomal dominant inheritance and is caused by mutations in the SEPT9 gene (SEPTIN9) located on chromosome 17 (17q25).
Prevalence
Rare
Diagnostic
Indication
Method
DNA sequence analysis of the exons as well as flanking intronic regions of the SEPT9 gene
Sample Requirement
2 - 4 ml of EDTA blood
Duration
4 - 6 weeks