© 1993 Oxford University Press
RESEARCH-ARTICLE |
Genetic heterogeneity for Duchenne-like muscular dystrophy (DLMD) based on linkage and 50 DAG analysis
o R. Oilvelra
Departamento de Bidogia, Instituto de Bociências, Universidade de So Paulo C P 11461, CEP 05422 - 970, So Paulo, S P, Brazil
1Department of Human Genetics, Leiden University The Netherlands
2Howard Hughes Medcal Institute, Department of Physiology and Biophysics, University of Iowa, College of Medicine Iowa City, LA 52242, USA
3Faculdade de Medicina, Universidade de So Paulo So Paulo, S P , Brazil
*To whom correspondence should be addressed
Received July 26, 1993; Revised September 7, 1993; Accepted September 7, 1993
Duchenne-like muscular dystrophy (DLMD) is an autosomal recessive (AR) muscular dystrophy which presents a clinical course Indistinguishable from the Xp21 Duchenne muscular dystrophy or DMD. Recently, Othmane et al. (11), based on a linkage study with 13q12 markers in 3 highly inbred DLMD families from Tunisia, suggested that the gene for this myopathy lies in the pericentromeric region of chromosome 13q. It is unknown if there is genetic heterogeneity causing the DLMD phenotype. Therefore, the aim of the present report is to describe the results of linkage analysis in 4 Brazillan DLMD families with 13q12 markers (D13S115 and D13S120), which were also tested for 50DAG. It was possible to exclude the 13q gene at 
= 0.10 as responsible for the DLMD phenotype in our families using both 13q12 markers, if the lod scores of each family were added up. Interestingly, 3 families were deficient for 50 DAG while one showed a positive pattern for this glycoproteln. Therefore, these results suggest: a) the DLMD phenotype is caused by more than one recessive gene; b) a gene, not located at 13q, causes deficiency of 50 DAG as a primary or secondary defect.