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Schwartz-Jampel syndrome: clinical, electromyographic and genetic studies
B Ishpekova1, M Rasheva, M Moskov
1University Hospital, Department of Neurology, Sofia.
Insights
This study describes chondrodystrophic myotonia in two sisters, highlighting early-onset myotonia, muscular weakness, and severe contractures. The findings emphasize the importance of early diagnosis for this rare genetic disorder.
Area of Science:
- Genetics
- Neurology
- Pediatrics
Background:
- Chondrodystrophic myotonia is a rare genetic disorder.
- Early diagnosis and understanding of its presentation are crucial for patient management.
Observation:
- Two sisters from a consanguineous family presented with early-onset myotonia and progressive muscular weakness within the first year of life.
- Clinical manifestations included facial dysmorphism, joint contractures, kyphoscoliosis, and abnormal gait.
- Electromyography (EMG) revealed spontaneous, continuous, high-frequency electrical discharges characteristic of myotonia.
Findings:
- The patients exhibited severe contractures, muscular weakness, and distinctive facial features.
- EMG findings were abnormal, showing a myotonic pattern in distal and proximal muscles.
- Normal nerve conduction studies (MCV and SCV) ruled out significant peripheral neuropathy.
Implications:
- This case report contributes to the understanding of chondrodystrophic myotonia's clinical spectrum.
- The findings underscore the genetic basis and progressive nature of the disorder.
- This is the first documented case of chondrodystrophic myotonia in Bulgaria, expanding its known geographical distribution.
Abstract:
Two sisters aged 9 and 7 from consanguineous parents are described. Both of them develop myotonia, muscular weakness as early as the first year after birth. At the age 3-4 a disturbed gait appeared due to knee joint contractures and limited joint movements. The children display facial dysmorphism (a small forehead, a flat base of the nose, a receding chin, an irregular order of the teeth, low-set ears, a high-arched palate, low hair-line), kyphoscoliosis, pigeon breast, severe contractures of the knee and elbow joint and foot deformities. The elder sister cannot walk. Hirsutism of all four limbs is found as well as sparse subcutaneous tissue. Muscles are stiff and firm. Tendon reflexes of the lower limbs are absent. Muscle enzymes show slightly increased values. The EMG needle examination in both sisters was abnormal. Spontaneous, continuous, high-frequency, low-voltage electrical discharges were observed in all distal and proximal muscles of the hands and legs. Some of them have a typical myotonic pattern. The MCV and the SCV was within the normal range. Both parents of our patients, their sister aged 4, as well as their grandparents showed no clinical and EMG abnormalities. All these data allow authors to affirm the diagnosis chondrodystrophic myotonia., described for the first time in Bulgaria.
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