Table 2.
Mean age of meeting milestone (years) among the patients who reported meeting the milestone by the time of study participation. Standard deviation and range are provided in parentheses and brackets
| Center for disease control and prevention (CDC) | CdLS group [15] |
NIPBL | SMC1A | Linear regression test results | ||
|---|---|---|---|---|---|---|
| Developmental milestones (approximate time when a child reaches a milestone) | Mean age in years (standard deviation)[range] | β, t-value, p value | r2 | |||
| Communication skill development | N = 17 | N = 11 | ||||
| Social smile | 2 Months | 3 Months | 0.95 (1.58)[0.5–6] | 0.61(0.22)[0.5–1] | β = -0.12, t = 0.57, n.s | n.s |
| Single syllable utterance | – | – | 1.22 (0.66)[1–3] | 1.35 (0.98)[0.5–3] | β = -0.04, t = 0.15, n.s | n.s |
| Single word | 15 Months | 18 Months | 1.50 (0.75)[1–3] | 2.50 (1.70)[0.5–6] | β = 0.38, t = 1.43, n.s | n.s |
| Two word sentences | 24 Months | 4.5 Years | 3.00 (1.87)[1–5] | 3.00 (0.00) | β = -0.68, t = 6.05, p = 0.002 | 0.95 |
| Motor development | N = 15 | N = 10 | ||||
| Support own head | 4 Months | – | 0.50 (0.00) | 0.55 (0.16)[0.5–1] | β = 0.25, t = 1.18, n.s | n.s |
| Sit | 9 Months | 12 Months | 1.45 (1.01)[0.5–3] | 1.62 (1.57)[0.5–5] | β = 0.05, t = 0.25, n.s | n.s |
| Crawl | – | – | 2.12 (1.09)[0.5–3] | 1.72 (0.90)[0.5–3] | β = -0.20, t = 0.86, n.s | n.s |
| Walk unassisted | 18 Months | 24 Months | 3.10 (2.60)[1–10] | 2.14 (1.06)[1–4] | β = 0.20, t = 0.78, n.s | n.s |
The table above includes milestones recently published by the CDC, which was defined as the time when 75% or more children can complete the skill by the age. Of note, these milestones are not meant to be used as developmental screening measures alone as highlighted by CDC [21], these were included to provide a qualitative comparison of our sample in addition to the heterogeneous sample of patients with CdLS published in Kline et al. [15]. The linear regression test results outlined above stem from linear regressions with age at survey completion controlled, gene variant group (NIPBL, SMC1A) as a predictor, and the developmental milestone as the dependent variable. The response option of < 12 months were coded as 0.5. Regression coefficient (r2) represents the proportion of variance of the developmental milestone explained by both the age at study participation and gene mutation
n.s. not significant (p > 0.10)