MUSCULAR DYSTROPHY IN CHILDHOOD. THE GENETIC ASPECT

Summary In a study of eighty‐three families of patients with primary muscular dystrophy the index cases are either children or patients in whom muscular weakness was first apparent in childhood. 106 patients examined by the authors are differentiated clinically into: Childhood type (ninety‐six patients examined) represented in seventy‐eight families. Two subgroups are distinguished: (1) Severe group with fifty‐six families in which all the affected members are boys. The group is genetically homogeneous, a sex‐linked recessive or, less probably a sex‐limited dominant gene being responsible. (2) Mild group with twenty‐two families; both sexes are represented amongst those affected. The group is genetically heterogeneous; sex‐linked recessive, autosomal recessive and dominant inheritance are probably all involved. Reasons are given to support the view that at least two sex‐linked or sex‐limited genes are concerned in the transmission of the childhood type of dystrophy. Adult types (ten patients examined) represented in five families. Inheritance is probably dominant in three families and possibly autosomal recessive in two. An Appendix containing summarized case histories is placed in the archives of the Galton Laboratory. The authors wish to thank Prof. W. S. Craig and Dr C. O. Carter for their generous advice and encouragement, and the University of Leeds for contributing towards the expense involved in travelling to the homes of patients. In addition one of us (H.B.) was in receipt of a grant from the Eugenics Society 1953–55. A special debt of gratitude is owed to Paediatricians in the Leeds Region who without exception, gave the authors every facility for studying patients under their care. It is a pleasure to acknowledge equally generous assistance from Dr Hugh Garland who allowed the authors to consult his hospital records. We are obliged to the Leeds City Coroner for permission to consult reports of two autopsy examinations. The majority of patients were traced with the unfailing co‐operation of the Medical Officers of the local authorities concerned, many of whom consulted with the authors and made available their school records. Permission to visit patients was invariably requested from the family doctor concerned and was in no case denied and the authors express their appreciation for the tolerance and kindness with which their efforts were rewarded by the parents and relations of children examined. Finally, the authors wish to thank Prof. Penrose for his advice and Miss M. N. Karn for her interest and help in the preparation of this paper.