A 71-nucleotide deletion in the periaxin gene in a Romani patient with early-onset slowly progressive demyelinating CMT.

BACKGROUND: Mutations in the periaxin (PRX) gene cause autosomal recessive demyelinating neuropathy Charcot-Marie-Tooth (CMT) type 4F. To date, 10 non-sense or frameshift PRX mutations have been reported in patients with early-onset neuropathy and further disease course consistent with either Dejerine-Sottas neuropathy or slow-progressive demyelinating CMT. METHODS: We sequenced 59 patients from 55 Czech families including four unrelated patients of Romani (Gypsy) origin with early-onset CMT displaying decreased nerve conduction velocities. RESULTS: We identified a novel homozygous mutation c.3286_3356del71 (K1095fsX18) in one Romani patient showing very slow disease progression. Amongst non-Romani Czech CMT patients, PRX mutations have been proven to be very rare.

GDAP1 mutations in Czech families with early-onset CMT.

Mutations in the ganglioside-induced differentiation associated protein-1 gene (GDAP1) cause autosomal recessive (AR) demyelinating or axonal Charcot-Marie-Tooth neuropathy (CMT). In order to establish the spectrum and frequency of GDAP1 mutations in Czech population, we sequenced GDAP1 in 74 Czech patients from 69 unrelated families with early-onset demyelinating or axonal CMT compatible with AR inheritance. We identified three isolated patients with GDAP1 mutations in both alleles. In one additional sporadic and one familial case, the second pathogenic mutation remained unknown. Overall, we detected two different mutations, a novel R191X nonsense and a L239F missense mutation. L239F previously described in a German-Italian family is a prevalent mutation in Czech population and we give evidence for its common ancestral origin. All Czech GDAP1 patients developed involvement of all four limbs evident by the end of second decade, except for one isolated patient showing very slow disease progression. All patients displayed axonal type of neuropathy.