Delayed diagnosis in duchenne muscular dystrophy: data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet).
OBJECTIVE
To identify key factors for the delay in diagnosis of Duchenne muscular dystrophy (DMD) without known family history.


METHODS
The cohort comes from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet), a multistate, multiple-source, population-based surveillance system that identifies and gathers information on all cases of Duchenne and Becker muscular dystrophy born since 1982. We analyzed medical records of 453 Duchenne and Becker muscular dystrophy boys to document the time course and steps taken to reach a definitive diagnosis.


RESULTS
Among 156 boys without known family history of DMD prior to birth, first signs or symptoms were noted at a mean age of 2.5 years. Concerns resulted in primary care provider evaluation of the child at a mean age of 3.6 years. Mean age at time of initial creatine kinase was 4.7 years. Mean age at definitive diagnosis of DMD was 4.9 years.


CONCLUSIONS
There is a delay of about 2.5 years between onset of DMD symptoms and the time of definitive diagnosis, unchanged over the previous 2 decades. This delay results in lost opportunities for timely genetic counseling and initiation of corticosteroid treatment. We recommend checking creatine kinase early in the evaluation of boys with unexplained developmental delay.
Ciafaloni
Emma
E
Department of Neurology, University of Rochester, Rochester, NY, USA. Emma_ciafaloni@urmc.rochester.edu
Fox
Deborah J
DJ
Pandya
Shree
S
Westfield
Christina P
CP
Puzhankara
Soman
S
Romitti
Paul A
PA
Mathews
Katherine D
KD
Miller
Timothy M
TM
Matthews
Dennis J
DJ
Miller
Lisa A
LA
Cunniff
Christopher
C
Druschel
Charlotte M
CM
Moxley
Richard T
RT
D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D042241:Early Diagnosis; D006801:Humans; D007223:Infant; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis*; D011159:Population Surveillance; D012189:Retrospective Studies; D013997:Time Factors