CLINICAL HETEROGENEITY OF ADHALIN DEFICIENCY

We report adhalin deficiency in 8 patients with clinically diagnosed m uscular dystrophy, dystrophic histopathological features, high plasma creatine kinase levels, normal expression of dystrophin, and marked va riability of symptoms. Although the distribution of hyposthenia was si milar in all 8 patients and predominantly involved muscles in the pelv ic girdle, age at onset and rate of disease progression were highly va riable: In 2 patients onset, at ages 24 and 25, was later than has bee n previously observed. We found no apparent relation between disease s everity and the quantity of adhalin expressed. Two kinds of myopathy w ith adhalin deficiency have been reported: one caused by a mutation in the adhalin gene on chromosome 17 (primary adhalinopathy) and the oth er linked to chromosome 13. The product of the gene on chromosome 13 i s probably associated with adhalin and its deficiency results in secon dary adhalinopathy. The severity of clinical phenotypes in these adhal inopathies seems to relate more to the kind and site of the mutations than to the residual amount of the protein. We also detected a variabl e reduction in the laminin beta 1 subunit by immuno-histochemistry in most patients, confirming that this is commonly associated with adhali n deficiency.