TABLE 1

Clinical Characteristics at Baseline for All Infants

All Subjects (N = 22)Control Group (n = 12)GH-Treated Group (n = 10)P (Control Versus GH)
Gender (M/F), n14/89/35/5.44
Ethnicity (Dutch/non-Dutch),a n19/310/29/1.57
Genetic subtype (deletion/UPD/unknown), n10/9/35/4/35/5/01.0
Age, mean (SD), mo12.9 (7.1)11.7 (6.3)14.2 (8.1).43
Age at start of GH, mean (SD), mo17.5 (7.3)18.0 (6.6)17.1 (13.6).85
Height, mean (SD), SDS−1.8 (1.2)*−2.0 (1.1)−1.6 (1.2).40
Weight, mean (SD), SDS−1.3 (1.5)*−1.6 (1.5)−0.9 (1.6).29
Muscle thickness, mean (SD),SDS
 Biceps brachii−1.6 (0.7)*−1.5 (0.7)−1.7 (0.7).50
 Forearm flexors−1.3 (1.0)*−1.2 (0.9)−1.5 (1.1).55
 Quadriceps−1.6 (0.9)*−1.8 (1.0)−1.3 (0.8).23
 Tibialis anterior−1.5 (0.5)*−1.5 (0.5)−1.4 (0.5).81
Muscle strength,b mean (SD)
 IMS, N28.9 (14.1)26.7 (10.1)31.3 (17.7).47
 IMS%c58.1 (22.4)54.8 (14.3)61.7 (28.1).50
Motor performance, mean (SD)
 GMFM total score26.8 (18.9)23.7 (18.8)30.4 (19.3).43
  • * SDS significantly below 0, P ≤ .001. SDS, SD score; UPD, uniparental maternal disomy.

  • a All infants were born in The Netherlands, but 3 families came from the Middle East.

  • b Muscle strength could not be measured in all infants at baseline, because at the start of the study not all infants were able to perform the pulling task used to measure muscle strength because of motor developmental delay. We have therefore reported the results of the first measurement made at a mean age of 17.2 (±7.0) months, which is, in most infants, the first or second measurement of the trial.

  • c IMS% = (observed IMS/predicted IMS) × 100.