The milder phenotype of the dystrophin gene double deletions

• Published in: Acta neurologica Scandinavica Vol. 107; no. 6; pp. 400 - 404
• Main Authors: El-Harouni, A. A., Amr, K. S., Effat, L. K., Eassawi, M. L., Ismail, S., Gad, Y. Z., El-Awady, M. K.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Munksgaard International Publishers 01.06.2003; Blackwell
• Subjects: Biological and medical sciences; Biopsy; Disability Evaluation; Diseases of striated muscles. Neuromuscular diseases; double deletion; Duchenne muscular dystrophy; dystrophin; Dystrophin - analysis; Dystrophin - genetics; Gene Deletion; Genotype; Humans; Immunohistochemistry; Male; Medical sciences; Muscle, Skeletal - chemistry; Muscular Dystrophy, Duchenne - genetics; Mutation; Neurology; Phenotype; Tropical medicine; Chromosomal aberration; Human; Immunohistochemistry; Neuromuscular diseases; Nervous system diseases; Genotype; Striated muscle; Double; Genetic determinism; Genetic disease; Pathology; Phenotype; Gene; Duchenne muscular dystrophy; Deletion; Abnormal chromosome; Mutation; Dystrophin; Comparative study; double deletion
• ISSN: 0001-6314; 1600-0404
• DOI: 10.1034/j.1600-0404.2003.00072.x

Objectives – This study aimed to examine the genotype–phenotype correlation in Duchenne muscular dystrophy (MD) patients with double deletion (Ddel) mutations in comparison with those having single deletions (Sdel). Materials and methods – The study included 250 Duchenne/Becker MD male patients from whom the 10 Ddel patients were compared with 20 Sdel subjects of same age and disease durations. The patients were subjected to neurological examination including functional disability grading scale (FDGS), molecular analysis of the dystrophin gene and immunohistochemical studies of some muscle biopsies. Results – The mean FDGS value in the Ddel group was lower than that in Sdel patients. The Ddel patients had partial expression of dystrophin in their skeletal muscles, while Sdel cases showed complete absence of the protein. Conclusion – Patients with double deletion mutations within the dystrophin gene have a milder phenotype than patients harboring single deletions at either major or minor hot spots of the gene.