TY - JOUR
T1 - LAMA2 gene analysis in congenital muscular dystrophy
T2 - New mutations, prenatal diagnosis, and founder effect
AU - Di Blasi, Claudia
AU - Piga, Daniela
AU - Brioschi, Paolo
AU - Moroni, Isabella
AU - Pini, Antonella
AU - Ruggieri, Alessandra
AU - Zanotti, Simona
AU - Uziel, Graziella
AU - Jarre, Laura
AU - Della Giustina, Elvio
AU - Scuderi, Carmela
AU - Jonsrud, Christoffer
AU - Mantegazza, Renato
AU - Morandi, Lucia
AU - Mora, Marina
PY - 2005/10
Y1 - 2005/10
N2 - Objective: To determine if laminin-α2 deficiency is due to mutations in the LAMA2 gene or secondary to mutations in other congenital muscular dystrophy genes. Methods: We performed molecular analysis of LAMA2, by single-strand conformation polymorphism and sequencing, in 15 patients with undetectable or greatly reduced laminin-α2 expression. We also performed 4 prenatal diagnoses and investigated a founder effect. Results: We found 1 known and 9 previously undescribed LAMA2 mutations spanning all protein domains. These were nonsense or frameshifts causing laminin-α2 absence or, in 1 case, a homozygous missense mutation producing partial protein expression and milder phenotype. LAMA2 mutations were undetected in 5 patients, in 2 of whom FKRP mutations explained the phenotype. In 3 prenatal cases, the fetus was heterozygous for the mutation of interest and pregnancy continued; in 1 case, the fetus was affected and aborted. In 2 patients, the Cys967Stop mutation and identical haplotypes flanking the LAMA2 gene indicated a founder effect. Conclusions: The clinical phenotype was severe in most patients with LAMA2 mutations and associated with undetectable protein expression. One case with no protein and another with partial expression had milder phenotypes. Typical white matter alterations on magnetic resonance imaging were found in all patients with LAMA2 mutations, supporting the utility of magnetic resonance imaging in differential diagnosis. The founder mutation (Cys967Stop) probably originated in Albania. Genetic characterization of affected families is mainly of use for prenatal diagnosis.
AB - Objective: To determine if laminin-α2 deficiency is due to mutations in the LAMA2 gene or secondary to mutations in other congenital muscular dystrophy genes. Methods: We performed molecular analysis of LAMA2, by single-strand conformation polymorphism and sequencing, in 15 patients with undetectable or greatly reduced laminin-α2 expression. We also performed 4 prenatal diagnoses and investigated a founder effect. Results: We found 1 known and 9 previously undescribed LAMA2 mutations spanning all protein domains. These were nonsense or frameshifts causing laminin-α2 absence or, in 1 case, a homozygous missense mutation producing partial protein expression and milder phenotype. LAMA2 mutations were undetected in 5 patients, in 2 of whom FKRP mutations explained the phenotype. In 3 prenatal cases, the fetus was heterozygous for the mutation of interest and pregnancy continued; in 1 case, the fetus was affected and aborted. In 2 patients, the Cys967Stop mutation and identical haplotypes flanking the LAMA2 gene indicated a founder effect. Conclusions: The clinical phenotype was severe in most patients with LAMA2 mutations and associated with undetectable protein expression. One case with no protein and another with partial expression had milder phenotypes. Typical white matter alterations on magnetic resonance imaging were found in all patients with LAMA2 mutations, supporting the utility of magnetic resonance imaging in differential diagnosis. The founder mutation (Cys967Stop) probably originated in Albania. Genetic characterization of affected families is mainly of use for prenatal diagnosis.
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U2 - 10.1001/archneur.62.10.1582
DO - 10.1001/archneur.62.10.1582
M3 - Article
C2 - 16216942
AN - SCOPUS:26444454956
VL - 62
SP - 1582
EP - 1586
JO - Archives of Neurology
JF - Archives of Neurology
SN - 0003-9942
IS - 10
ER -