Table 2.
Craniofacial features of POLR3-HLD patients according to genotype
| Craniofacial features |
POLR3A
(n=16) |
POLR3B
(n=10) |
POLR1C
(n=4) |
p-value | p -value (3A vs 3B) |
p -value (3A vs 1C) |
p -value (3B vs 1C) |
| High anterior hairline | 8 (50.0) | 5 (50.0) | 0 | 0.171 | 1 | 0.068 | 0.078 |
| High forehead | 6 (37.5) | 4 (40.0) | 0 | 0.313 | 0.899 | 0.143 | 0.134 |
| Anomaly of the forehead* | 8 (50.0) | 6 (60.0) | 0 | 0.117 | 0.619 | 0.068 | 0.040 |
| Bitemporal narrowing | 3 (18.8) | 0 | 2 (50.0) | 0.072 | 0.145 | 0.197 | 0.016 |
| Hypertelorism | 6 (37.5) | 2 (20.0) | 1 (25.0) | 0.621 | 0.347 | 0.639 | 0.837 |
| Telecanthus | 1 (6.3) | 2 (20.0) | 1 (25.0) | 0.461 | 0.286 | 0.264 | 0.837 |
| Long palpebral fissures | 3 (18.8) | 4 (40.0) | 0 | 0.228 | 0.235 | 0.348 | 0.134 |
| Anomaly of the eyes† | 7 (43.8) | 7 (70.0) | 2 (50.0) | 0.422 | 0.191 | 0.822 | 0.480 |
| Low-set ears | 2 (12.5) | 2 (20.0) | 1 (25.0) | 0.787 | 0.606 | 0.531 | 0.837 |
| Flat midface | 10 (62.5) | 6 (60.0) | 2 (50.0) | 0.901 | 0.899 | 0.648 | 0.733 |
| Pinched nose | 6 (37.5) | 4 (40.0) | 1 (25.0) | 0.866 | 0.899 | 0.639 | 0.597 |
| Bulbous tip of the nose | 3 (18.8) | 1 (10.0) | 1 (25.0) | 0.752 | 0.547 | 0.780 | 0.469 |
| Anomaly of the nose‡ | 8 (50.0) | 4 (40.0) | 2 (50.0) | 0.875 | 0.619 | 1 | 0.733 |
| Short philtrum | 7 (43.8) | 3 (30.0) | 2 (50.0) | 0.713 | 0.483 | 0.822 | 0.480 |
| Smooth philtrum | 7 (43.8) | 8 (80.0) | 2 (50.0) | 0.185 | 0.069 | 0.822 | 0.262 |
| Anomaly of the philtrum§ | 13 (81.3) | 8 (80.0) | 4 (100) | 0.628 | 0.937 | 0.348 | 0.334 |
| Thin upper lip | 2 (12.5) | 6 (60.0) | 1 (25.0) | 0.036 | 0.011 | 0.531 | 0.237 |
| Full lower lip | 3 (18.8) | 4 (40.0) | 1 (25.0) | 0.490 | 0.235 | 0.780 | 0.597 |
| Anomaly of the lips¶ | 4 (25.0) | 7 (70.0) | 2 (50.0) | 0.076 | 0.024 | 0.329 | 0.480 |
| Short chin | 3 (18.8) | 3 (30.0) | 0 | 0.440 | 0.508 | 0.348 | 0.217 |
| Pointed chin | 9 (56.3) | 3 (30.0) | 3 (75.0) | 0.241 | 0.191 | 0.494 | 0.124 |
| Anomaly of the chin** | 12 (75.0) | 6 (60.0) | 3 (75.0) | 0.700 | 0.420 | 1 | 0.597 |
Pearson χ2 was used to investigate the association between the presence of craniofacial features and the genotype.
P-values are reported for the 3-group comparison (1st column) as well as 2-group comparisons (2nd, 3rd and 4th columns). A p-value below 0.05 suggest a statistical difference for the craniofacial feature prevalence between the groups and are shown in bold. P-values below 0.10 are shown in italic. Only features present in at least 10% of the sample (>3/31) were included for comparison. The individual carrying pathogenic variants in POLR3A and 1 pathogenic variant and 1 variant of unknown significance in POLR3B (subject 31) was excluded from the statistical analysis (n=30). Identified craniofacial features were also grouped based on their location.
*Anomaly of the forehead included a high anterior hairline or a high forehead.
†Anomaly of the eyes included hypertelorism, telecanthus or long palpebral fissures.
‡Anomaly of the nose included a pinched nose or a bulbous tip of the nose.
§Anomaly of the philtrum included a short or smooth philtrum.
¶Anomaly of the lips included a thin upper or a full lower lip.
**Anomaly of the chin included a short or pointed chin.