L239F founder mutation in GDAP1 is associated with a mild Charcot-Marie-Tooth type 4C4 (CMT4C4) phenotype.
Over 40 mutations in the GDAP1 gene have been shown to segregate with Charcot-Marie-Tooth disease (CMT). Among these, only two mutations, i.e., S194X and Q163X have been reported in a sufficient number of CMT families to allow for the construction of reliable phenotype-genotype correlations. Both the S194X and Q163X mutations have been shown to segregate with an early-onset and severe neuropathy resulting in loss of ambulance at the beginning of the second decade of life. In this study, we identified the L239F mutation in the GDAP1 gene in one Bulgarian and five Polish families. We hypothesized that the L239F mutation may result from a founder effect in the European population since this mutation has previously been reported in Belgian, Czech, and Polish patients. In fact, we detected a common disease-associated haplotype within the 8q13-q21 region in the Polish, German, Italian, Czech, and Bulgarian CMT families. Like the previously detected "regional" S194X and Q163X mutations, respectively present in Maghreb countries and in patients of Spanish descent, the L239F mutation seems to be the most common GDAP1 pathogenic variant in the Central and Eastern European population. Given the likely presence of a common ancestor harboring the L239F mutation, we decided to compare the phenotypes of the CMT (L239F) patients collected in this study with those of previously reported cases. In contrast to CMT4A caused by the S194X and Q163X mutations, the CMT phenotype resulting from the L239F substitution represents a milder clinical entity with a long-preserved period of ambulance at least until the end of the second decade of life.
Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
Dagmara
D
Kabzińska
Halina
H
Strugalska-Cynowska
Anna
A
Kostera-Pruszczyk
Barbara
B
Ryniewicz
Renata
R
Posmyk
Alina
A
Midro
Pavel
P
Seeman
Lucia
L
Báranková
Magdalena
M
Zimoń
Jonathan
J
Baets
Vincent
V
Timmerman
Velina
V
Guergueltcheva
Ivailo
I
Tournev
Stayko
S
Sarafov
Peter
P
De Jonghe
Albena
A
Jordanova
Irena
I
Hausmanowa-Petrusewicz
Andrzej
A
Kochański
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D005060:Europe; D005260:Female; D018703:Founder Effect; D056726:Genetic Association Studies; D056426:Genetic Loci; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D055815:Young Adult
C118663:GDAP protein; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D011506:Proteins; C488620:SH3TC2 protein, human