A new single-nucleotide deletion of PMP22 in an HNPP family without recurrent palsies.
In this study we describe four patients from the same kindred who were affected by an autosomal-dominantly inherited peripheral neuropathy. They presented an unusual combination of clinical, electrophysiological, and pathological findings in association with a new mutation of the PMP22 gene. Clinically, three patients had carpal tunnel syndrome symptoms and one patient had late-onset peroneal atrophy. Motor and sensory nerve conduction velocities were reduced without focal slowing at entrapment sites. Nerve biopsy disclosed diffuse hypomyelination with focal thickening of the myelin sheath in some fibers. Sequence analysis of the PMP22 gene showed a single-nucleotide deletion (227delG) in the affected patients. This mutation, which has not been reported previously, leads to an open reading frame shift and probably to a truncated and unstable PMP22 protein. We conclude that this novel 227delG mutation of PMP22 gives a mild form of hereditary neuropathy with liability to pressure palsy with atypical clinical and electrophysiological findings.
Luigetti
Marco
M
Istituto di Neurologia, Università Cattolica del Sacro Cuore, Pol. A Gemelli Largo Gemelli 8, Rome, Italy.
Conte
Amelia
A
Madia
Francesca
F
Mereu
Maria Lucia
ML
Zollino
Marcella
M
Marangi
Giuseppe
G
Pomponi
Maria Grazia
MG
Liberatore
Giuseppe
G
Tonali
Pietro Altilio
PA
Sabatelli
Mario
M
D000368:Aged; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D017353:Gene Deletion; D015417:Hereditary Sensory and Motor Neuropathy / Q000235:genetics* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009185:Myelin Proteins / Q000235:genetics*; D009431:Neural Conduction / Q000235:genetics; D017384:Sequence Deletion / Q000235:genetics*
D009185:Myelin Proteins; C073687:PMP22 protein, human