Further Studies Concerning the Detection of Carriership in the Duchenne Type of Dystrophy

Abstract

Serum creatine kinase (CPK) determinations, electromyography and electrocardiography were performed on a material of 192 female relatives of boys with Duchenne’s dystrophy. CPK, which gives the highest detectability of carriership, scored only up to 66% in the present material, even among known carriers (50% in possible). Electromyography and electrocardiography, when applied separately, played a minor part in detection of the carrier state. CPK determination in the daughters improved carriership detectability substantially (by 27%) in the mothers; the CPK activity may be raised in the daughter even when it is normal in the mother. In establishing, and especially in excluding, carriership combined methods should be employed and all female relatives of a suspected mother should be tested, especially her daughters.

The female carrier of Duchenne muscular dystrophy.

“…Electrocardiographic abnormalities,8 27 changes on quantitative electromyography,28-30 and pathological changes in the muscle under light3' 32 or electron microscopy3334 have also been used as supplementary tests for detecting carriers; and some authors have favoured combined tests. [34][35][36][37] All these methods detect only some carriers; but an abnormality on one test, such as abnormal histological appearances of muscle, may occur with normal activities of creatine kinase and vice versa.34 38 Careful quantification of histochemical and histological features on needle biopsy in obligate carriers and volunteer controls has helped to standardise the methods and to identify significant deviation in fibre size, fibre type, and internal nuclei. 38 On clinical examination several features may be found in carriers, ranging from prominence of the calves (often unilateral) through muscle cramps or minimal weakness to overt muscle wasting and weakness.…”