©istock.com/Andrea Obzerova
Interdisciplinary CompetenceMolecular Diagnostics
Know how in the analysis of genetic material.
For the benefit of patients.

IllnessNeuropathy, hereditary motor-sensory, demyelinating; type I - step 1


Short information

Curated analysis of PMP22 duplication (or deletion)

Number of genes
1 Accredited laboratory test
Examined sequence length
0,5 kb (Core-/Core-canditate-Genes)
- (Extended panel: incl. additional genes)
Analysis Duration
on request
  • EDTA-anticoagulated blood (3-5 ml)
Diagnostic indications

only +


Gene panel

Selected genes

NameExon Length (bp)OMIM-GReferenz-Seq.Heredity

Informations about the disease

Clinical Comment

Hereditary motor and sensory neuropathies (HMSN) or Charcot-Marie-Tooth (CMT) disorders and related neuropathies are a group of clinically and genetically heterogeneous conditions that primarily affect the peripheral nervous system with secondary muscle wasting and weakness. CMT is the most common inherited neuromuscular disorder. CMT-patients can present with various symptoms, usually with motor signs predominating over sensory symptoms in all age groups. CMT can begin in infancy, present in adolescence or be lifelong with mild symptoms - even asymptomatic relatives can be detected in respective families. Motor nerve conduction velocities (NCV) distinguish two main types: CMT1 (demyelinating; NCV<35m/sec) and CMT2 (axonal; NCV>45m/sec). CMT1 accounts for approximately 2/3 of all CMT cases. CMT neuropathies can be inherited either autosomal dominant, recessive or X-linked (CMTX forms) or occur sporadically. To date, over 60 different genetic loci have been associated with the categories CMT1-4, CMTX and CMTdi (dominant intermediate type; NCV 35-45m/sec). Almost all of the relevant genes have been identified. With up to 80%, PMP22 gene mutations are the most common cause of CMT1, mostly a PMP22 duplication is present. PMP22 gene testing includes point mutations as well as the PMP22 deletion in hereditary neuropathy with a tendency to pressure paralysis (HNPP). Negative molecular genetic results also do not exclude clinical diagnosis especially because of CMT1 genetic heterogeneity.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1358/


  • "Allelic": HNPP
  • "Allelic": Hereditary neuropathy with liability to pressure palsies
  • "Allelisch": Hereditäre Neuropathie mit Neigung zu Drucklähmungen
  • Charcot-Marie-Tooth type I; CMT1A
  • Hereditary motor sensory neuropathy, type I; HMSNIA
  • Polyneuropathy
Heredity, heredity patterns etc.
  • AD
ICD10 Code

Bioinformatics and clinical interpretation

No text defined