0000000000417108
AUTHOR
Marja-liisa Savontaus
X-Linked myopathy with excessive autophagy: A new hereditary muscle disease
We report on 3 brothers with a myopathy that also affected their maternal grandfather and great-uncle. Characteristic features are onset in early childhood, very slow progression, normal life expectancy, weakness of proximal limb muscles, especially in the legs, elevation of serum creatine kinase, and no cardiac or intellectual involvement. In biopsy material muscle fibers are almost never necrotic but show excessive autophagic activity and exocytosis of the phagocytosed material. We suggest that this family has an undescribed type of congenital myopathy, for which we propose the name X-linked myopathy with excessive autophagy.
Human cationic amino acid transporter gene hCAT-2 is assigned to 8p22 but is not the causative gene in lysinuric protein intolerance
Lysinuric protein intolerance (LPI) is a recessively inherited amino acid disorder characterized by defective efflux of cationic amino acids at the basolateral membrane of the intestinal and renal tubular epithelium. Recently, cDNAs encoding the related proteins hCAT-2A and hCAT-2B have been cloned. These two carrier proteins are most likely the product of the same gene, hCAT-2. Using the hCAT-2B cDNA, we assigned the hCAT-2 gene to chromosome 8p22. Furthermore, by linkage analysis in Finnish LPI families, we ruled out that hCAT-2B is involved in LPI disease.