Delayed diagnosis and genetic testing in spinal muscular atrophy: a case series

Figures

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  Figure 1.. Current clinical condition of case 3. (A) The patient’s proximal muscles in the upper and lower limbs were significantly atrophied and weakened; (B) Pseudohypertrophy of the gastrocnemius muscles in the lower extremities. Permission was obtained from the patient to be published for these photos for research purposes.

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  Figure 2.. Electromyography results of case 3. (A) Motor nerves conduction velocity: the CMAP amplitude in the tibial nerve was decreased; (B) Sensory nerves conduction velocity: normal. (C) MUAP (motor unit action potential) Spontaneous activity: abnormal muscle fiber potentials seen as fibrillatory potentials and positive sharp waves; motor unit potentials had prolonged and increased wave amplitudes; polyphase wave: increased, issued at a simple phase frequency.

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  Figure 3.. Genetic testing of SMN1 gene and SMN2 gene of case 3, 4, and 5. (A) The results showed a deletion of exon 7 in the SMN1 gene and three copies of the SMN2 gene. (B) The results showed deletion of exon 7 and 8 in the SMN1 gene and four copies of exon 7/8 in the SMN2 gene. (C) The results showed deletion of exon 7 and 8 in the SMN1 gene and four copies of exon 7/8 in the SMN2 gene.

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  Figure 4.. Families’ pedigree of case 4 and 5. Roman numerals represent the generations. Arabic numerals identify individuals. Arrows indicate the probands. II.3 represents case 4, and II.4 represents case 5.