Charcot-Marie-Tooth (CMT) disease caused by mutations in the GDAP1 gene has been 
shown to be inherited via traits that may be either autosomal recessive (in the 
majority of cases) [CMT4A] or autosomal dominant [CMT2K]. CMT4A disease is 
characterized by an early onset, and a severe clinical course often leading to a 
loss of ambulation, whereas CMT2K is characterized by a mild clinical course of 
benign axonal neuropathy beginning even in the 6th decade of life. Clinical data 
from a GDAP1 mutated patient suggests that the presence of a particular mutation 
is associated with a certain trait of inheritance. The association of a 
particular GDAP1 gene mutation and a dominant or recessive trait of inheritance 
is of special importance for genetic counseling and the prenatal diagnostics as 
regards severe forms of CMT. In the present study we report on two CMT families 
in which a newly identified Glu222Lys mutation within the GDAP1 gene segregates 
both in autosomal dominant and recessive traits. Our study shows that at least 
some GDAP1 gene mutations may segregate with the CMT phenotype as both dominant 
and recessive traits. Thus, genetic counseling for CMT4A/CMT2K families requires 
more extensive data on GDAP1 phenotype-genotype correlations.