Dr.Subbulakshmi P S, Dr.Sheela Nampoothiri, Dr.Dhanya Yasodharan, (Paed Genetics)Dr.C. Jayakumar
AIMS, Kochi
Six years old male child presented with difficulty in climbing and takes support of the rails for the past 3 years.
He also had difficulty in getting up from sitting position for 2 years.
No history of muscle fasiculations /trauma /seizures/ urinary discoloration was noted.He was referred to our hospital for further evaluation and management.
He’s the first child of Non-consangious marriage. It was a full term vaginal delivery and ba cried immediately after birth with uneventful postnatal period. Age appropiate milestones were attained and the child was apparently normal till 3 years after birth.
Growth parameters were within normal limit. Immunizations were up-to date according to NIS. No family h/o TB, immunodeficiencies. H/O similar illness in mother’s uncle was noted.
On examination, the child had hypertrophy of the calf muscles bilaterally. The child had a waddling gait and when asked to stand up from the floor he does it with the support of his hands on the floor initially and then on his own knees (Gower sign +).
The vital parameters were within normal limits. Systemic examination showed slight decrease in power and tone in both the lower limbs with Upper limb being normal and DTR was 2+ in all 4 limbs. Clinical examination of the heart was normal and all the other systemic examinations were normal.
DIFFERENTIALS:
⦁ Duchenne muscular dystrophy
⦁ Polymyositis
⦁ Benign hypotonia
⦁ Spinal muscular atrophy
⦁ Congenital myopathies
⦁ Progressive paresis
⦁ Limble girdle Muscular dystrophy
⦁ Metabolic Myopathies
⦁ Mitochondrial Myopathies
In view of the positive Gower sign, lordotic/waddling gait and calf muscle hypertrophy and the age of presentation, Duchenne was strongly suspected.
Initial Labs:
SGOT/SGPT : 194/395
Creatinine Kinase: 10,998
Lactate: 0.99
TC: 12.6, N: 31, L: 48, Hb: 12.3, Platelets: 267
ECG: Normal
Echo : Normal study
NCV: Normal study
In view of the strong suspicion of Duchenne, MLPA-79 exons were sent and reports awaited. The child is enrolled in physiotherapy and kept under followup.
DISCUSSION:
Duchenne muscular dystrophy (DMD) is a Autosomal recessive disorder characterized progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact.
DMD is one of four conditions known as dystrophinopathies. The other three diseases that belong to this group are Becker Muscular dystrophy (BMD, a mild form of DMD); an intermediate clinical presentation between DMD and BMD; and DMD-associated dilated cardiomyopathy (heart-disease) with little or no clinical skeletal, or voluntary, muscle disease.
DMD symptom onset is in early childhood, usually between ages 2 and 3. The disease primarily affects boys, but in rare cases it can affect girls. Muscle weakness is the principal symptom of DMD. It can begin as early as age 2 or 3, first affecting the proximal muscles (those close to the core of the body) and later affecting the distal limb muscles (those close to the extremities).
Usually, the lower external muscles are affected before the upper external muscles. The affected child might have difficulty jumping, running, and walking. Other symptoms include enlargement of the calves, a waddling gait, and lumbar lordosis (an inward curve of the spine). Later on, the heart and respiratory muscles are affected as well. Progressive weakness and scoliosis result in impaired pulmonary function, which can eventually cause acute respiratory failure.
Diagnosis is both clinically and Genetic tests such as MLPA, blood tests like Creatinine kinase level and muscle biopsies can also be done. There’s currently no cure for Duchene muscular dystrophy (DMD), so the main goal of treatment is to manage symptoms and improve quality of life.
Supportive therapies include:
1. Corticosteroids: Corticosteroids, such prednisolone is beneficial for delaying muscle strength loss, improving lung function, delaying scoliosis, slowing the progression of cardiomyopathy (heart weakness) and prolonging survival.
2. Medication to treat cardiomyopathy: Early treatment with ACE Inhibitors and/or beta blockers may slow the progression of cardiomyopathy and prevent the onset of heart failure.
3. Physical therapy and exercises.
4. Surgery to release contractures if present.
TAKE-HOME MESSAGE:
Duchenne muscular dystrophy (DMD) is a severe, progressive genetic disorder characterized muscle degeneration and weakness, primarily affecting boys. Early diagnosis and multidisciplinary care, including physical therapy and medications, can improve quality of life and extend life expectancy.