[Prevalence of myotonic dystrophy in Iceland].
OBJECTIVE
Epidemiologic studies of Myotonic Dystrophy (Dystrophic Myotony, DM) have shown variable regional prevalence from 0,46 to 189/105. We carried out a total population survey of DM in Iceland in 2004 having Oct. 31 as the day of prevalence.


METHODS
Patients were collected from multiple sources, including Landspitali University Hospital registry and through contact with neurologists, neuropaediatricians, paediatricians and rehabilitation specialists. All EMGs of DM patients were reviewed. Information was gathered about age, age of onset, family history of DM and clinical symptoms.


RESULTS
Eighty-two patients were ascertained giving a crude prevalence of 28.2/105. The prevalence of the congenital form of DM was 7.9/105 (23 patients, 26%). Affected females outnumbered males with a gender ratio of 1.2:1 (NS). Mean age of onset of symptoms for those, who didn't have the congenital form was 27.5 years (range 5-70 years). Ten families with DM were identified and all prevalent patients belonged to those families.


CONCLUSIONS
The prevalence of DM is high in Iceland and higher than generally reported. This study showed a three times higher total prevalence and a seven times higher prevalence of congenital DM than found in a previous study in Iceland. We believe that this increase in prevalence probably reflects increased awareness of inherited diseases in neonates and better detection of patients who have mild symptoms.
Leifsdóttir
Gerour
G
Háskóli Islands, Laeknadeild.
Benedikz
John E G B
JE
Jóhannesson
Guojón
G
Jónsson
Jón Jóhannes
JJ
Sveinbjörnsdóttir
Sigurlaug
S
D000328:Adult; D017668:Age of Onset; D000368:Aged; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009224:Myotonia Congenita / Q000175:diagnosis / Q000453:epidemiology*; D009223:Myotonic Dystrophy / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012042:Registries; D017678:Sex Distribution