Table 3.
SMA-affected infants identified by NBS.
| Case | SMN2 Copy Number (from Diagnostic Lab) | Age at Specimen Collection/Receipt by NBS/When Screening Result Communicated (Days of Life) | Prenatal Testing | Clinical Status Reported by PCP at Time of NBS Report | Age at First Visit to Specialist (Days of Life) | Clinical Status Reported by Specialist at First Evaluation | Treatment Type | Age at First Treatment (Days of Life) | Current Age (Months) | Current Clinical Status |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 2/2/3 | Both parents known carriers | Well | 26 | No symptoms | Nusinersen | 38 | 24 | Normal developmental progression for age |
| 2 | 4 | 2/4/5 | Well; gaining weight but not quite back up to birthweight | 5 | Tongue fasciculations and mild generalized hypotonia | Onasemnogene abeparvovec | 171 | 22 | Continues to develop normally without symptoms or signs of SMA | |
| 3 | 2 | 2/4/4 | Both parents known carriers | Poor tone | 6 | Hypotonia, decreased movements, head lag and slip through on exam; Respiratory insufficiency, bell shaped chest, paradoxical breathing | Onasemnogene abeparvovec | 18 | 19.5 | Moderate motor delays; sits unassisted, rolls over, moderate head control, cannot lift head from a prone position; able to transfer objects hand to hand. Cannot bear full weight on legs, no crawling or walkingAble to chew and swallow, no secretion problems |
| 4 | 2 | 1/3/6 | Well | 9 | Day of life (DOL) 7 normal echo and microcephaly per medical records and + axillary slip; DOL 9 tongue fasciculations and impaired swallowing, generalized weakness and hypotonia | Nusinersen/Onasemnogene abeparvovec/Risdiplam | 16/29/309 | 19 | At 15 months, crawling, sitting independently, pulls to stand; walks with a walker. Although required g-tube initially, now 100% oral feeder | |
| 5 | 2 | 1/2/3 | Premature but well; no SMA concerns | 7 | Paradoxical breathing and tongue fasciculations | Nusinersen/Onasemnogene abeparvovec | 11/98 | 13 | At 1 years old, continues to acquire age-appropriate motor milestones: rolling, sitting unsupported, crawling | |
| 6 | 2 | 2/3/6 | Extremely dislocatable left hip, low muscle tone | 8 | No symptoms | Onasemnogene abeparvovec | 29 | 12 | Mild motor delays (probably in part due to bracing for hip dislocation) | |
| 7 | 4 | 1/2/3 | Prenatal diagnosis | Status reported as already under the care of a specialist | 0 | No symptoms | Nusinersen | 8 | 10 | Remains asymptomatic at 9 months of age |
| 8 | 2 | 2/2/3 | One parent known carrier | Well | 13 | Tongue fasciculations and reduced deep tendon reflexes | Onasemnogene abeparvovec | 13 | 5.5 | At 4 months, continues to acquire improved tone and head control in prone and supported sitting positions and recently began eating purees |
| 9 | 2 | 2/5/6 | Both parents known carriers | Well | 7 | Limited movements of bilateral lower extremities | Onasemnogene abeparvovec | 19 | 5 | Weakness of bilateral lower extremities left > right |