Clinical and Molecular Profile of Duchenne Muscular Dystrophy (DMD): Case-Record Analysis From Uttar Pradesh, India

To assess the clinical and molecular profile of patients with Duchenne Muscular Dystrophy (DMD) presenting to a tertiary center in Eastern Region of Uttar Pradesh, India.

In this retrospective study, case records of all patients diagnosed as DMD were analyzed to ascertain the clinical phenotype and molecular profile. Multiplex polymerase chain reaction (mPCR) technique, Multiplex Ligation Dependent Probe Amplification (MLPA) and Next Generation Sequencing (NGS) were used for establishing the molecular diagnosis. Leiden Open Variation Database (LOVD) frame checker online tool was used to predict clinical severity of the cases.

Records of 112 children with DMD were analyzed. The median (IQR) age of onset and clinical presentation of disease was 60 (12, 132) months and 90 (33, 156) months, respectively. The most common clinical presentations were difficulty in standing from sitting position (n = 107), difficulty in climbing stairs (n = 106), and difficulty in walking (n = 99). Bilateral calf muscle hypertrophy and a positive Gower's sign was seen in 110 and 108 patients at presentation. The median (IQR) creatinine phosphokinase (CPK) levels at diagnosis were 6296.5 (4320, 7432.5) U/L. The genetic variation in 111 patients were reported as deletion (n = 105), duplication (n = 3), and point variation (n = 3). 22 patients could benefit from the available exon skipping therapy. Exondys (exon 51 skipping) could be used in 14 patients.

Deletions were recorded in a much higher proportion of patients compared to previous studies from India. There were 22 patients who could have been benefitted by the available exon skipping therapy.