Also, approximately half of the patients with congenital muscular dystrophy show deficiency of a component of the muscular extracellular matrix.(merosin/laminin-alpha 2).
Deficiencies of adhalin in a particular form of limb-girdle muscular dystrophy, and of merosin in a particular form of congenital muscular dystrophy as well as the newly discovered principle of abnormal tri-nucleotide repeats in myotonic dystrophy are evidence of progress that has also amplified the notion of the dystrophinopathies that the protein-deficient muscular dystrophies can now be considered examples of contributions of the dystrophin-glycoprotein complex across the muscle fiber plasma membrane.
Analogous to the putative perturbation of the anchoring function of the dystrophin-associated complex in congenital muscular dystrophy with mutations in the alpha 2-subunit of laminin, our observations suggest a similar mechanism in Bethlem myopathy.
Approximately half the cases of classical congenital muscular dystrophy (CMD) have a pronounced deficiency or absence of the laminin alpha 2 chain of laminin-2 (merosin).
Approximately half of the cases with the classical form of congenital muscular dystrophy (CMD) have a deficiency of the laminin alpha 2 chain, encoded by the LAMA2 gene on chromosome 6q22.
Complete or partial deficiency of the laminin alpha2 chain of merosin has been demonstrated in a proportion of children with classical congenital muscular dystrophy and linkage to the laminin alpha2 chain gene (LAMA2) on chromosome 6q2 has been established.
A group of transmembrane proteins known as alpha- (adhalin) beta-, gamma- and delta-sarcoglycan are deficient in autosomal recessive limb-girdle muscular dystrophy, and the extracellular matrix protein merosin (alpha2-laminin), is deficient in a subset of patients with congenital muscular dystrophy.
PCR based mutation screening of the laminin alpha2 chain gene (LAMA2): application to prenatal diagnosis and search for founder effects in congenital muscular dystrophy.
Deficiency of laminin alpha2 chain caused by mutations of the LAMA2 gene on chromosome 6q2 account for approximately 50% of cases of congenital muscular dystrophy (CMD) in white patients.
By either mechanism the phenotype of congenital muscular dystrophy is believed to be the result of disruption of linkage between the extracellular matrix and the dystrophin glycoprotein complex.
We evaluated transforming growth factor-beta1 (TGF-beta1) expression in the muscle of four laminin alpha2-negative, four laminin alpha2-positive and seven partial laminin alpha2-deficient congenital muscular dystrophy (CMD) patients, and compared it to Duchenne muscular dystrophy (DMD) patients and controls.
Mutations in the fukutin-related protein gene (FKRP) cause a form of congenital muscular dystrophy with secondary laminin alpha2 deficiency and abnormal glycosylation of alpha-dystroglycan.
Mutations in the fukutin-related protein gene (FKRP) identify limb girdle muscular dystrophy 2I as a milder allelic variant of congenital muscular dystrophy MDC1C.
Mutations in the fukutin-related protein gene (FKRP) cause a form of congenital muscular dystrophy with secondary laminin alpha2 deficiency and abnormal glycosylation of alpha-dystroglycan.