Asymptomatic hyperCKemia in a case of Danon disease due to a missense mutation in Lamp-2 gene.
Primary lysosome-associated membrane protein-2 (LAMP-2) deficiency is an X-linked disease, characterized by the clinical triad of cardiomyopathy, vacuolar myopathy and mental retardation, previously known as Danon disease. Mutations of lamp-2 gene have been reported so far in about 20 patients, one of whom was Italian. We describe a new Italian case with persistent hyperCKemia, exercise intolerance and hypertrophic cardiomyopathy but with no muscle weakness or mental impairment. Muscle biopsy revealed a vacuolar myopathy with mild glycogen storage, and immunohistochemical studies detected LAMP-2 deficiency. A new nucleotide substitution (T961C) on exon 8 of lamp-2 gene was identified as responsible for the protein deficiency. This is the first missense mutation so far described. LAMP-2 deficiency should be considered as a cause of recurrent hyperCKemia and hypertrophic cardiomyopathy.
Musumeci
Olimpia
O
Department of Neurosciences, Psychiatry and Anesthesiology, University of Messina, Messina, Italy. om471@yahoo.com
Rodolico
Carmelo
C
Nishino
Ichizo
I
Di Guardo
Giuseppe
G
Migliorato
Alba
A
Aguennouz
Mohammed
M
Mazzeo
Anna
A
Messina
Corrado
C
Vita
Giuseppe
G
Toscano
Antonio
A
D000328:Adult; D015703:Antigens, CD / Q000235:genetics*; D001706:Biopsy; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics* / Q000473:pathology; D003402:Creatine Kinase / Q000097:blood*; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics* / Q000473:pathology; D051907:Lysosomal Membrane Proteins; D008297:Male; D020125:Mutation, Missense; D014617:Vacuoles / Q000473:pathology
D015703:Antigens, CD; D051907:Lysosomal Membrane Proteins; D003402:Creatine Kinase