Two cases of spinal muscular atrophy type I that received early treatment and achieved improved prognosis by promoting multi-center, multi-professional collaboration after prenatal diagnosis

<p>  Spinal muscular atrophy (SMA) is a hereditary lower motor neuron disease. Traditionally prenatal diagnosis has been performed for genetic testing in the first trimester of pregnancy of a child with type I or type II SMA, if the parents wish and if they have a good understanding of the significance of the test. In the past, most pregnancies were terminated when the disease was discovered due to lack of treatment options. However, the significance of prenatal diagnosis is changing now that several disease-modifying drugs are now covered by insurance. In this report, we describe two cases in which prenatal diagnosis was performed in collaboration with a medical facility in the patient’s place of residence for cases in remote areas, and early introduction of postnatal treatment was successfully achieved. Case 1 is a 28-month-old girl and case 2 is a 12-month-old boy. Case 1’s older brother was diagnosed with SMA type Ib and Case 2’s older brother with SMA type Ia. Since both cases tested positive for prenatal genetic testing (affected), we confirmed the parents’ intention to deliver and treat the children, and established a postnatal treatment system in collaboration with the hospital in their area of residence. Case 1 had respiratory irregularities, so nusinersen treatment was started at the local hospital on the 9th day of life, and onasemnogene abeparvovec was administered at 3 months and 21 days of age. Case 2 had tendon reflex loss from birth, so nusinersen treatment was started at the hospital of residence on the second day of life, and onasemnogene abeparvovec was administered on the 11th day of life. Case 1 achieved independent ambulation at 11 months of age and was able to jump at 26 months. Case 2 achieved independent sitting at 12 months of age. We believe that prenatal diagnosis of SMA will be conducted with the aim of establishing a complete treatment system at the time of positive (affected) cases, as in these two cases.</p>