Spinal Muscular Atrophy (SMA) Biomarkers Study in the Immediate Postnatal Period of Development

Describe & compare the distribution of motor function assessments over the first two years of life in SMA vs. healthy control infants.

The TIMPSI is used to assess the postural and selective control of movement typically used by infants younger than 5 months. The TIMPSI scores were related to an infant's ability to reach. The TIMPSI is a 29-item evaluation that contains 3 item sets: a Screening set, an Easy set, and a Hard set. The Screening set consists of 11 items from the TIMP, each with a 5- to 7-point rating scale; the Easy set has 6 items with 5- or 6-point rating scales and 4 dichotomously scored items; the Hard set has 8 items, 3 with 5-point rating scales and 5 items that are scored dichotomously. The Total score is derived from all subset scores and is the sum of those subset scores. The final score could range from 0 to 99 points. The higher the score the better the functional ability of the participant. Linear mixed effects models were used for analyses.

The TIMPSI motor function testing was done during all of the study visits knowing that the healthy controls would eventually ceiling out. The study design allowed for secondary motor function tests based on the score of the TIMPSI. If infants scored a 41 or above on the TIMPSI they would be tested with the AIMS. If they were below they were tested with the CHOP-INTEND. The CHOP-INTEND is a reliable and validated, comprehensive assessment of the postural and selective control of movement needed by infants. It is a clinician-rated questionnaire developed to assess motor skill in spinal muscular atrophy type I. The 16 items are scored from 0 to 4. The global score ranges from 0 to 64, a higher score indicating better motor skills.(Finkel, McDermott, 2014). All healthy controls based upon scores at 6 months moved on to the AIMS test, therefore no healthy controls completed the CHOP-INTEND. Linear mixed effects models were used for analyses of Motor function outcome data.

Linear mixed effects models were used for analyses.

The reason that the number of infants differ from those in participant flow is based upon the protocol. The selection of which secondary test to perform depended upon the score of the TIMPSI that was performed. TIMPSI <41, do CHOP-NTEND. TIMPSI > 41, do AIMS.

The AIMS incorporates the neuromaturational concept and the dynamical systems theory and is used to measure gross motor maturation of infants from birth through the age of independent walking (Piper, Pinnell et al. 1992, Piper, Darrah et al 1994). In the AIMS, the impact of neurological components on motor development is reflected by a sequence of motor skills, which are used as the basis of assessment. The AIMS consists of 58 items, including 4 positions: prone (21 items), supine (9 items), sitting (12 items) & standing(16 items). The highest score available is 58. The higher the score the better the functional ability of the participant.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA vs. healthy control infants.

Maximum ulnar CMAP amplitude and area will be obtained by recording from the abductor digitiminimi muscle following ulnar nerve stimulation at the wrist. All electrophysiologic testing will be performed by certified electromyographers experienced in the assessment of pediatric patients. Maximum values for both negative peak (NP) amplitude and NP area will be obtained. No medications will be used.

This test is done routinely in this population. Pediatric electrodes and each site's standard electromyograph devices will be utilized. The test, while not considered to be painful, may cause some discomfort similar to a static electric shock. Infants may whimper or cry due to the surprise of the shock. Each shock lasts approximately 0.1 millisecond. The testing duration is expected to be approximately 30 seconds.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA vs. healthy control infants.

Results were measured in survival motor neurons (SMN), hypoxanthine phosphoribosyltransferase (HPRT) Ratio.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA vs. healthy control infants.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA vs. healthy control infants.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and CHOP-INTEND. In the CHOP-INTEND analyses, correlations were not estimable for the 18 and 24 month visits.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and CHOP-INTEND.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and CHOP-INTEND. In the CHOP-INTEND analyses, the correlation at the 24 month visit was not estimable.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and CHOP-INTEND.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and AIMS.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and AIMS.

In these analyses motor function score was the outcome measure. Correlation was defined as the estimated mean increase per a one unit increase in the biomarker under consideration. A linear mixed effects model was used to estimate the correlation between the biomarker and motor function score. Separate models were used for the TIMPSI and AIMS.

Examine whether any of the motor function assessments, putative physiological, or molecular biomarkers predict risk of death in the SMA cohort. Proportional hazards regression models used to determine if motor function scores, mRNA, and protein levels predict death in SMA subjects. Considered each predictor separately modeled as a time-varying covariate (predictor values were allowed to vary as time to death was assessed).

Describe and compare the distribution of motor function assessments over the first two years of life in SMA subjects with SMN copy number = 2 versus healthy control infants.

The TIMPSI is used to assess the postural and selective control of movement typically used by infants younger than 5 months. The TIMPSI scores were related to an infant's ability to reach. The TIMPSI is a 29-item evaluation that contains 3 item sets: a Screening set, an Easy set, and a Hard set. The Screening set consists of 11 items from the TIMP, each with a 5- to 7-point rating scale; the Easy set has 6 items with 5- or 6-point rating scales and 4 dichotomously scored items; the Hard set has 8 items, 3 with 5-point rating scales and 5 items that are scored dichotomously. The Total score is derived from all subset scores and is the sum of those subset scores. The final score could range from 0 to 99 points. The higher the score the better the functional ability of the participant.

Describe and compare the distribution of motor function assessments over the first two years of life in SMA subjects with SMN copy number = 2 versus healthy control infants.

The CHOP-INTEND is a reliable and validated, comprehensive assessment of the postural and selective control of movement needed by infants. It is a clinician-rated questionnaire developed to assess motor skill in spinal muscular atrophy type I. The 16 items are scored from 0 to 4. The global score ranges from 0 to 64, a higher score indicating better motor skills.(Finkel, McDermott, 2014).

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA2 vs. healthy control infants.

Maximum ulnar CMAP amplitude and area will be obtained by recording from the abductor digitiminimi muscle following ulnar nerve stimulation at the wrist. All electrophysiologic testing will be performed by certified electromyographers experienced in the assessment of pediatric patients. Maximum values for both negative peak (NP) amplitude and NP area will be obtained. No medications will be used.

This test is done routinely in this population. Pediatric electrodes and each site's standard electromyograph devices will be utilized. The test, while not considered to be painful, may cause some discomfort similar to a static electric shock. Infants may whimper or cry due to the surprise of the shock. Each shock lasts approximately 0.1 millisecond. The testing duration is expected to be approximately 30 seconds.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA vs. healthy control infants.

Describe and compare the distribution of the putative physiological and molecular biomarkers over the first two years of life in SMA2 vs. healthy control infants.

Describe and compare the distribution of motor function assessments over the first two years of life in SMA subjects with SMN copy number = 2 versus healthy control infants

Examine the correlation between each of the putative physiological and molecular biomarkers with the TIMPSI and CHOP-INTEND over the first two years of life in SMA (SMN = 2). All estimated correlations are the same at each study visit.

Examine the correlation between each of the putative physiological and molecular biomarkers with the TIMPSI and CHOP-INTEND over the first two years of life in SMA (SMN = 2). All estimated correlations are the same at each study visit.

Examine the correlation between each of the putative physiological and molecular biomarkers with the TIMPSI and CHOP-INTEND over the first two years of life in SMA (SMN = 2). All estimated correlations are the same at each study visit.

Examine the correlation between each of the putative physiological and molecular biomarkers with the TIMPSI and CHOP-INTEND over the first two years of life in SMA (SMN = 2). All estimated correlations are the same at each study visit.