Aim To determine epidemiological and clinical characteristics of spinal muscular atrophy (SMA), one of the most common autosomal recessive diseases in Tunisia.
Results During a 21-year period (1987–2008), 26 patients (11 females and 15 males) suffering from SMA were hospitalised in our paediatric unit. They belong to 20 different families. 65% of patients came from Sfax. The mean age at diagnosis was 5.26 months. Consanguinity was noted in 73% of cases. A similar previous familial history was found in 54.2% of cases. The SMA was type I in 84.6% of cases, type II in 11.5% of cases and type III in 4.8% of cases. Respiratory distress and general hypotonia were the common presenting symptoms (87.6% of cases). Deep tendon reflexes were absent in all patients, axial and peripheral hypotonia was also obvious in all cases; thoracic deformation was noted in 19.2. Electromyography when performed has showed signs of neurogenic muscle atrophy. Muscle biopsy, performed in 42% of cases, has showed typical fascicular atrophy. Genetic analysis was done in 13 infants and showed the deletions of the telomeric copy of the SMN gene. Antenatal diagnosis was successful in four families whose fetuses were all healthy. During the follow-up, 65.4% of our patients had developed severe respiratory complications leading to death at a mean age of 12.1 months.
Conclusion SMA is frequent in our country because of the high rate of consanguinity. Antenatal diagnosis must be easily proposed to families with a history of SMA to avoid the recurrence of this disease.