Table 1 Clinical features of individuals with RNU4-2 variants according to the location of the variants in the different U4 functional domains
Parameters | Total | n.64_65insT | n.76C>T | Other variants in the T-loop or RBM42 interaction region | Other variants in the stem III | |
|---|---|---|---|---|---|---|
Patients | 146a | 106 | 10 | 20 | 9 | |
With clinical data | 143a | 103 | 10 | 20 | 9 | |
Prenatal findings | 70/125 (56%) | 55/92 (60%) | 3/10 (30%) | 9/17 (53%) | 3/6 (50%) | |
IUGR | 41/131 (31.3%) | 28/94 (30%) | 1/9 (11%) | 9/20 (45%) | 3/8 (38%) | |
Cerebral abnormalities | 29/91 (31.87%) | 27/82 (33%) | 0/1 (0%) | 2/6 (33%) | 0/2 (0%) | |
Neonatal findings | 115/140 (82.14%) | 93/102 (91%) | 2/10 (20%) | 17/20 (85%) | 3/8 (38%) | |
Neonatal hypotonia | 88/138 (63.77%) | 71/100 (71%) | 0/10 (0%) | 15/20 (75%) | 2/8 (25%) | |
Neonatal feeding problems | 73/138 (52.9%) | 58/101 (57%) | 1/10 (10%) | 12/19 (63%) | 2/8 (25%) | |
Congenital microcephaly | 30/122 (24.59%) | 24/87 (28%) | 1/9 (11%) | 3/19 (16%) | 2/7 (29%) | |
Microcephaly | 97/141 (68.79%) | 76/103 (74%) | 3/10 (30%) | 15/19 (79%) | 3/9 (33%) | |
Short stature | 72/140 (51.43%) | 61/102 (60%) | 1/10 (10%) | 9/19 (47%) | 1/9 (11%) | |
Walking | Not achieved | 16/115 (13.91%) | 11/83 (13%) | 0/10 (0%) | 5/13 (38%) | 0/9 (0%) |
Delay | 82/115 (71.3%) | 65/83 (78%) | 6/10 (60%) | 7/13 (54%) | 4/9 (44%) | |
Normal age | 17/115 (14.78%) | 7/83 (8%) | 4/10 (40%) | 1/13 (8%) | 5/9 (56%) | |
Language ability | Nonverbal | 61/116 (52.59%) | 52/85 (61%) | 0/10 (0%) | 9/12 (75%) | 0/9 (0%) |
Few words | 31/116 (26.72%) | 29/85 (34%) | 0/10 (0%) | 1/12 (8%) | 1/9 (11%) | |
Simple sentences | 16/116 (13.79%) | 3/85 (4%) | 6/10 (60%) | 1/12 (8%) | 6/9 (67%) | |
Normal | 8/116 (6.9%) | 1/85 (1%) | 4/10 (40%) | 1/12 (8%) | 2/9 (22%) | |
Developmental delay | Severe | 87/134 (64.93%) | 73/99 (74%) | 0/9 (0%) | 13/18 (72%) | 1/8 (12%) |
Moderate | 37/134 (27.61%) | 24/99 (24%) | 4/9 (44%) | 5/18 (28%) | 4/8 (50%) | |
Mild | 9/134 (6.72%) | 2/99 (2%) | 5/9 (56%) | 0/18 (0%) | 2/8 (25%) | |
No | 1/134 (0.75%) | 0/99 (0%) | 0/9 (0%) | 0/18 (0%) | 1/8 (12%) | |
Estimated level of ID | Severe | 73/112 (65.18%) | 61/78 (78%) | 0/8 (0%) | 12/17 (71%) | 0/9 (0%) |
Moderate | 31/112 (27.68%) | 16/78 (21%) | 4/8 (50%) | 5/17 (29%) | 6/9 (67%) | |
Mild | 8/112 (7.14%) | 1/78 (1%) | 4/8 (50%) | 0/17 (0%) | 3/9 (33%) | |
Autism spectrum disorder | 52/92 (56.52%) | 43/69 (62%) | 2/7 (29%) | 5/11 (45%) | 2/5 (40%) | |
Epilepsy | 81/140 (57.86%) | 57/102 (56%) | 6/10 (60%) | 11/19 (58%) | 7/9 (78%) | |
Febrile seizures | 56/81 (69.14%) | 40/60 (67%) | 8/8 (100%) | 4/7 (57%) | 4/6 (67%) | |
Status epilepticus | 20/68 (29.41%) | 17/51 (33%) | 0/5 (0%) | 3/9 (33%) | 0/3 (0%) | |
Drug-resistance | 12/72 (16.67%) | 10/52 (19%) | 0/6 (0%) | 2/8 (25%) | 0/6 (0%) | |
Abnormal brain MRI | 107/130 (82.31%) | 89/98 (91%) | 1/7 (14%) | 15/18 (83%) | 2/7 (29%) | |
Enlarged ventricles | 58 | 54 | 0 | 4 | 0 | |
Corpus callosum abnormality | 66 | 53 | 1 | 11 | 1 | |
Cardiac abnormalities | 21/112 (18.75%) | 15/85 (18%) | 1/8 (12%) | 4/14 (29%) | 1/5 (20%) | |
Renal/genitourinary abnormalities | 24/110 (21.82%) | 17/83 (20%) | 1/5 (20%) | 5/16 (31%) | 1/6 (17%) | |
Bone/skeletal anomalies | 42/123 (34.15%) | 35/92 (38%) | 1/9 (11%) | 4/16 (25%) | 2/6 (33%) | |
Eyes/vision abnormalities | 70/124 (56.45%) | 59/95 (62%) | 0/6 (0%) | 7/15 (47%) | 4/8 (50%) | |
Hearing loss | 9/125 (7.2%) | 6/91 (7%) | 0/7 (0%) | 3/18 (17%) | 0/9 (0%) | |
Teeth/dental anomalies | 19/99 (19.19%) | 13/72 (18%) | 1/7 (14%) | 3/14 (21%) | 2/6 (33%) | |
Skin abnormalities | 28/115 (24.35%) | 20/84 (24%) | 3/7 (43%) | 4/17 (24%) | 1/7 (14%) | |
Feeding issues | 80/125 (64%) | 63/91 (69%) | 1/7 (14%) | 13/18 (72%) | 3/9 (33%) | |
Failure to thrive | 65/126 (51.59%) | 51/93 (55%) | 2/7 (29%) | 10/18 (56%) | 2/8 (25%) | |
Constipation | 63/123 (51.22%) | 51/90 (57%) | 2/8 (25%) | 8/18 (44%) | 2/7 (29%) | |
Joint hyperlaxity | 46/112 (41.07%) | 37/82 (45%) | 0/7 (0%) | 6/15 (40%) | 3/8 (38%) | |
Acrocyanosis | 18/108 (16.67%) | 16/79 (20%) | 0/6 (0%) | 2/16 (12%) | 0/7 (0%) | |
Blood count abnormality | 15/93 (16.13%) | 13/69 (19%) | 0/7 (0%) | 1/12 (8%) | 1/5 (20%) | |
