DUCHENNE MUSCULAR DYSTROPHY AND ITS EARLY DIAGNOSIS. RELEVANCE, PROBLEMATICS, POSSIBILITIES, PROSPECTS

Abstract

Duchenne muscular dystrophy (DMD) is an orphan neuromuscular progressive genetic disease that causes muscle breakdown and subsequent loss. Provided early diagnosis, complex standard and pathogenetic therapy significantly changes the trajectory of the disease, making it more benign. Diagnosis of DMD is a two-pillar system with creatine kinase (CK) level measured at the first stage followed by molecular genetic study in case the enzyme threshold values. The quality of genetic diagnostics in Russia has reached the best worldwide standards recently though identifying children with elevated CK levels is yet difficult. The number of diagnosed DMD patients in Russia is significantly lower than the statistically estimated global amount. The average age for diagnosis is not decreasing either. Thus, the median age for DMD and Becker muscular dystrophy (BMD) molecular diagnosis is 7 years and 8 months old. The number of identified children below the age of 2 y/o in Russia has remained consistently low over the past three years. According to the results of a familial cases survey, the correct primary diagnosis of DMD was established in less than half of all cases, 47.1%. The most common incorrect diagnoses were as follows: asymptotic hepatitis (25.1%), perinatal damage to the central nervous system (6.4%), cerebral palsy (2.7%), autism spectrum disorder (ASD) (2.7%) and flat feet, hallux valgus etc. (16% in total). The median duration between the initial DMD manifestation and molecular diagnosis is 3 years and 8 months as yet whilst the age-specific guidelines suggest prescribing standard and pathogenetic therapy during the 2 to 5 y/o period of life. Therefore, the Russia’s average age of DMD diagnosis above 7 y/o lies far beyond the optimal age for initiating of the DMD therapy with the purpose of gaining its maximum possible clinical benefit. The accumulated international and Russian experience demonstrates the possibility for improving of the primary DMD and BMD diagnosis in early preschool age and therefore requires its nationwide introduction.