Duchenne and Becker Muscular Dystrophy: Contribution of a Molecular and Immunohistochemical Analysis in Diagnosis in Morocco

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders caused by mutations of the DMD gene located at Xp21. In DMD patients, dystrophin is virtually absent; whereas BMD patients have 10% to 40% of the normal amount. Deletions in the dystrophin gene represent 65% of mutations in DMD/BMD patients. To explain the contribution of immunohistochemical and genetic analysis in the diagnosis of these dystrophies, we present 10 cases of DMD/BMD with particular features. We have analyzed the patients with immunohistochemical staining and PCR multiplex to screen for exons deletions. Determination of the quantity and distribution of dystrophin by immunohistochemical staining can confirm the presence of dystrophinopathy and allows differentiation between DMD and BMD, but dystrophin staining is not always conclusive in BMD. Therefore, only identification involved mutation by genetic analysis can establish a correct diagnosis

A rapid polymerase chain reaction-based test for screening Steinert's disease (DM1)

Myotonic dystrophy (DM) is a multisystemic neuromuscular disorder caused by a dynamic mutation of (CTG) trinucleotide repeats in the 3′ untranslated region of the myotonic dystrophy protein kinase gene (DMPK). The aim of the present study was to establish the use of polymerase chain reaction (PCR)-based simple and rapid method for initial sample screening. Only a minority of samples were tested positive with the above method and need to be detected by tri primer (TP)-PCR and Southern blotting which is more time consuming and involves use of radioactive material. This study concerned 24 patients from nine families with a clinical diagnosis of the DM1. DNA extracted from the blood was used for amplification of the triplet repeat sequences at the DMPK loci. We obtained two bands for the normal subjects and one band for patients corresponding to normal DMPK allele, confirmed by the TP-PCR and the Southern blot. This rapid test for initial screening of samples for the presence of DMPK mutations is economical and reliable method. This method reduces the number of samples needing TP-PCR and Southern blotting

A rapid polymerase chain reaction-based test for screening Steinert's disease (DM1)

Myotonic dystrophy (DM) is a multisystemic neuromuscular disorder caused by a dynamic mutation of (CTG) trinucleotide repeats in the 3′ untranslated region of the myotonic dystrophy protein kinase gene (DMPK). The aim of the present study was to establish the use of polymerase chain reaction (PCR)-based simple and rapid method for initial sample screening. Only a minority of samples were tested positive with the above method and need to be detected by tri primer (TP)-PCR and Southern blotting which is more time consuming and involves use of radioactive material. This study concerned 24 patients from nine families with a clinical diagnosis of the DM1. DNA extracted from the blood was used for amplification of the triplet repeat sequences at the DMPK loci. We obtained two bands for the normal subjects and one band for patients corresponding to normal DMPK allele, confirmed by the TP-PCR and the Southern blot. This rapid test for initial screening of samples for the presence of DMPK mutations is economical and reliable method. This method reduces the number of samples needing TP-PCR and Southern blotting